diff --git a/src/lib/dom-api-flush.html b/src/lib/dom-api-flush.html
index 8c0ae43b53..1ecc1821e6 100644
--- a/src/lib/dom-api-flush.html
+++ b/src/lib/dom-api-flush.html
@@ -16,10 +16,18 @@
     _FLUSH_MAX: 100,
     _needsTakeRecords: !Polymer.Settings.useNativeCustomElements,
     _debouncers: [],
+    _preFlushList: [],
     _finishDebouncer: null,
 
     // flush and debounce exposed as statics on Polymer.dom
     flush: function() {
+      for (var i=0; i < this._preFlushList.length; i++) {
+        this._preFlushList[i]();
+      }
+      this._flush();
+    },
+
+    _flush: function() {
       // flush debouncers
       for (var i=0; i < this._debouncers.length; i++) {
         this._debouncers[i].complete();
@@ -34,7 +42,7 @@
       // flush again if there are now any debouncers to process
       if (this._debouncers.length && this._flushGuard < this._FLUSH_MAX) {
         this._flushGuard++;
-        this.flush();
+        this._flush();
       } else {
         if (this._flushGuard >= this._FLUSH_MAX) {
           console.warn('Polymer.dom.flush aborted. Flush may not be complete.')
@@ -52,6 +60,18 @@
       }
     },
 
+    addPreflush: function(fn) {
+      this._preFlushList.push(fn);
+    },
+
+    // TODO(sorvell): Map when we can?
+    removePreflush: function(fn) {
+      var i = this._preFlushList.indexOf(fn);
+      if (i >= 0) {
+        this._preFlushList.splice(i, 1);
+      }
+    },
+
     addDebouncer: function(debouncer) {
       this._debouncers.push(debouncer);
       // ensure the list of active debouncers is cleared when done.
diff --git a/src/lib/dom-api-mutation-content.html b/src/lib/dom-api-mutation-content.html
index 438f5fc9b7..bf13de0130 100644
--- a/src/lib/dom-api-mutation-content.html
+++ b/src/lib/dom-api-mutation-content.html
@@ -15,113 +15,85 @@
     var DomApi = Polymer.DomApi.ctor;
     var Settings = Polymer.Settings;
 
-    DomApi.prototype.observeDistributedNodes = function(callback) {
-      if (!this._observer) {
-        this._observer = new DomApi.Mutation(this);
-      }
-      return this._observer.addObserver(callback);
-    };
-
-    DomApi.prototype.unobserveDistributedNodes = function(handle) {
-      if (this._observer) {
-        this._observer.removeObserver(handle);
-      }
-    }
-
     DomApi.MutationContent = function(domApi) {
-      this.domApi = domApi;
-      this.node = this.domApi.node;
-      this._observers = [];
-      this._addedNodes = [];
-      this._removedNodes = [];
+      DomApi.Mutation.call(this, domApi);
     };
 
-    DomApi.MutationContent.prototype = {
-
-      // addObserver: function(callback) {
-      //   return this._observers.push(callback);
-      // },
-
-      // removeObserver: function(handle) {
-      //   this._observers.splice(handle - 1, 1);
-      // },
-
-      // hasObservers: function() {
-      //   return Boolean(this._observers.length);
-      // },
-
-      // _scheduleMutationNotify: function() {
-      //   this._mutationDebouncer = Polymer.Debounce(this._mutationDebouncer, 
-      //     this._notifyObservers);
-      //   this._mutationDebouncer.context = this;
-      //   Polymer.dom.addDebouncer(this._mutationDebouncer);
-      // },
-
-      // _notifyObservers: function(mxns) {
-      //   var info = {
-      //     target: this.node,
-      //     addedNodes: this._addedNodes,
-      //     removedNodes: this._removedNodes
-      //   }
-      //   var o$ = this._observers;
-      //   for (var i=0, o; (i < o$.length) && (o=o$[i]); i++) {
-      //     o.call(null, info);
-      //   }
-      //   this._addedNodes = [];
-      //   this._removedNodes = [];
-      // }
-
-      // observeDistributedNodes: function(callback) {
-      //   if (this.node.localName !== 'content') {
-      //     console.warn('Must call `observeDistributedNodes` on a <content> element.');
-      //     return;
-      //   }
-      //   // setup <content>.getDistributedNodes observation
-      //   if (!this.hasObservers()) {
-      //     this._startObserveDistributedNodes();
-      //   }
-      //   this._addObserver(callback);
-      // },
-
-      // unobserveDistributedNodes: function(handle) {
-      //   if (this.node.localName !== 'content') {
-      //     return;
-      //   }
-      //   this._removeObserver(handle);
-      //   if (!this.hasObservers()) {
-      //     this._stopObservingDistributedNodes();
-      //   }
-      // },
-
-      // _startObservingDistributedNodes: function() {
-      //   this._distributedObservers = [];
-      //   var root = this.getOwnerRoot();
-      //   var host = root && root.host;
-      //   if (host) {
-      //     var h = Polymer.dom(host)
-      //       .observeChildren(this._scheduleDistributedNodesNotify);
-      //     this._distributedObservers.push(h);
-      //   }
-      // },
-
-      // _stopObservingDistributedNodes: function() {
-        
-      // },
-
-      // _scheduleDistributedNodesNotify: function() {
-      //   this._distributedNodesDebouncer = 
-      //     Polymer.Debounce(this._distributedNodesDebouncer, 
-      //     this._notifyObservers);
-      //   this._distributedNodesDebouncer.context = this.node;
-      //   Polymer.dom.addDebouncer(this._distributedNodesDebouncer);
-      // },
+    DomApi.MutationContent.prototype = Object.create(DomApi.Mutation.prototype);
+
+    Polymer.Base.extend(DomApi.MutationContent.prototype, {
+
+      addListener: function(callback, includeChanges) {
+        this._includeChanges = includeChanges;
+        var h = DomApi.Mutation.prototype.addListener.call(this, callback);
+        this._scheduleNotify();
+        return h;
+      },
+
+      notifyIfNeeded: function() {
+        if (this._hasListeners()) {
+          this._scheduleNotify();
+        }
+      },
+
+      _notify: function() {
+        var info = this._includeChanges ? this._calcChanges() : {};
+        if (info) {
+          info.target = this.node;
+          this._callListeners(info);
+        }
+      },
+
+      _calcChanges: function() {
+        var changes = {
+          addedNodes: [],
+          removedNodes: []
+        };
+        var o$ = this.node.__distributedNodes = this.node.__distributedNodes ||
+          [];
+        var n$ = this.domApi.getDistributedNodes();
+        this.node.__distributedNodes = n$;
+        var splices = Polymer.ArraySplice.calculateSplices(n$, o$);
+        // process removals
+        for (var i=0, s; (i<splices.length) && (s=splices[i]); i++) {
+          for (var j=0, n; (j < s.removed.length) && (n=s.removed[j]); j++) {
+            changes.removedNodes.push(n);
+          }
+        }
+        // process adds
+        for (var i=0, s; (i<splices.length) && (s=splices[i]); i++) {
+          for (var j=s.index; j < s.index + s.addedCount; j++) {
+            changes.addedNodes.push(n$[j]);
+          }
+        }
+        if (changes.addedNodes.length || changes.removedNodes.length) {
+          return changes;
+        }
+      }
 
-    };
+    });
 
     if (Settings.useShadow) {
-
+      
+      Polymer.Base.extend(DomApi.MutationContent.prototype, {
+        
+        _ensureObserver: function() {
+          var root = this.domApi.getOwnerRoot();
+          var host = root && root.host;
+          if (host) {
+            this._observer = Polymer.dom(host).observeNodes(
+              this.notifyIfNeeded.bind(this));
+          }
+        },
+
+        _cleanupObserver: function() {
+          if (this._observer) {
+            Polymer.dom(host).unobserveNodes(this._observer);
+          }
+        }
+
+      });
     
-
     }
 
 })();
diff --git a/src/lib/dom-api-mutation.html b/src/lib/dom-api-mutation.html
index cd8e825c27..5d0f6dc47c 100644
--- a/src/lib/dom-api-mutation.html
+++ b/src/lib/dom-api-mutation.html
@@ -15,129 +15,119 @@
     var DomApi = Polymer.DomApi.ctor;
     var Settings = Polymer.Settings;
 
-    DomApi.prototype.observeChildren = function(callback) {
-      if (!this._observer) {
-        this._observer = new DomApi.Mutation(this);
-      }
-      return this._observer.addObserver(callback);
-    };
-
-    DomApi.prototype.unobserveChildren = function(handle) {
-      if (this._observer) {
-        this._observer.removeObserver(handle);
-      }
-    }
-
     DomApi.Mutation = function(domApi) {
       this.domApi = domApi;
       this.node = this.domApi.node;
-      this._observers = [];
+      this._listeners = [];
       this._addedNodes = [];
       this._removedNodes = [];
     };
 
     DomApi.Mutation.prototype = {
 
-      addObserver: function(callback) {
-        return this._observers.push(callback);
+      addListener: function(callback) {
+        this._ensureObserver();
+        return this._listeners.push(callback);
       },
 
-      removeObserver: function(handle) {
-        this._observers.splice(handle - 1, 1);
+      removeListener: function(handle) {
+        this._listeners.splice(handle - 1, 1);
+        if (!this._hasListeners()) {
+          this._cleanupObserver();
+        }
       },
 
-      hasObservers: function() {
-        return Boolean(this._observers.length);
+      _ensureObserver: function() {
+        this._observeContentElements(this.domApi.childNodes);
+      },
+
+      // TODO(sorvell): unobserver content?
+      _cleanupObserver: function() {},
+
+      _hasListeners: function() {
+        return Boolean(this._listeners.length);
       },
 
       addNode: function(node) {
-        if (this.hasObservers()) {
+        if (this._hasListeners()) {
           this._addedNodes.push(node);
-          this._scheduleMutationNotify();
+          this._scheduleNotify();
         }
       },
 
       removeNode: function(node) {
-        if (this.hasObservers()) {
+        if (this._hasListeners()) {
           this._removedNodes.push(node);
-          this._scheduleMutationNotify();
+          this._scheduleNotify();
         }
       },
 
       addAllNodes: function() {
-        if (this.hasObservers()) {
+        if (this._hasListeners()) {
           var c$ = this.domApi.childNodes;
-          for (var i=0, c; (i < c$.length) && (c=c$[i]); i++) {
-            this.addNode(c);
+          if (c$.length) {
+            for (var i=0, c; (i < c$.length) && (c=c$[i]); i++) {
+              this._addedNodes.push(c);
+            }
+            this._scheduleNotify();
           }
         }
       },
 
-      _scheduleMutationNotify: function() {
-        this._mutationDebouncer = Polymer.Debounce(this._mutationDebouncer, 
-          this._notifyObservers);
-        this._mutationDebouncer.context = this;
-        Polymer.dom.addDebouncer(this._mutationDebouncer);
+      _scheduleNotify: function() {
+        this._debouncer = Polymer.Debounce(this._debouncer, 
+          this._notify);
+        this._debouncer.context = this;
+        Polymer.dom.addDebouncer(this._debouncer);
       },
 
-      _notifyObservers: function(mxns) {
+      _notify: function(mxns) {
         var info = {
           target: this.node,
           addedNodes: this._addedNodes,
           removedNodes: this._removedNodes
         }
-        var o$ = this._observers;
-        for (var i=0, o; (i < o$.length) && (o=o$[i]); i++) {
-          o.call(null, info);
-        }
+        this._updateContentElements(info);
+        this._callListeners(info);
         this._addedNodes = [];
         this._removedNodes = [];
-      }
+      },
 
-      // observeDistributedNodes: function(callback) {
-      //   if (this.node.localName !== 'content') {
-      //     console.warn('Must call `observeDistributedNodes` on a <content> element.');
-      //     return;
-      //   }
-      //   // setup <content>.getDistributedNodes observation
-      //   if (!this.hasObservers()) {
-      //     this._startObserveDistributedNodes();
-      //   }
-      //   this._addObserver(callback);
-      // },
-
-      // unobserveDistributedNodes: function(handle) {
-      //   if (this.node.localName !== 'content') {
-      //     return;
-      //   }
-      //   this._removeObserver(handle);
-      //   if (!this.hasObservers()) {
-      //     this._stopObservingDistributedNodes();
-      //   }
-      // },
-
-      // _startObservingDistributedNodes: function() {
-      //   this._distributedObservers = [];
-      //   var root = this.getOwnerRoot();
-      //   var host = root && root.host;
-      //   if (host) {
-      //     var h = Polymer.dom(host)
-      //       .observeChildren(this._scheduleDistributedNodesNotify);
-      //     this._distributedObservers.push(h);
-      //   }
-      // },
-
-      // _stopObservingDistributedNodes: function() {
-        
-      // },
+      _updateContentElements: function(info) {
+        this._observeContentElements(info.addedNodes);
+        this._unobserveContentElements(info.removedNodes);
+      },
 
-      // _scheduleDistributedNodesNotify: function() {
-      //   this._distributedNodesDebouncer = 
-      //     Polymer.Debounce(this._distributedNodesDebouncer, 
-      //     this._notifyObservers);
-      //   this._distributedNodesDebouncer.context = this.node;
-      //   Polymer.dom.addDebouncer(this._distributedNodesDebouncer);
-      // },
+      _observeContentElements: function(elements) {
+        for (var i=0, h, n; (i < elements.length) && (n=elements[i]); i++) {
+          if (n.localName === 'content') {
+            n.__observeNodesMap = n.__observeNodesMap || new WeakMap();
+            if (n.__observeNodesMap.get(this) === undefined) {
+              h = Polymer.dom(n).observeNodes(
+                this._callListeners.bind(this), true);
+              n.__observeNodesMap.set(this, h);
+            }
+          }
+        }
+      },
+
+      _unobserveContentElements: function(elements) {
+        for (var i=0, n, h; (i < elements.length) && (n=elements[i]); i++) {
+          if (n.localName === 'content') {
+            h = n.__observeNodesMap.get(this);
+            if (h) {
+              Polymer.dom(n).unobserveNodes(h);
+            }
+          }
+        }
+      },
+
+      _callListeners: function(info) {
+        var o$ = this._listeners;
+        for (var i=0, o; (i < o$.length) && (o=o$[i]); i++) {
+          o.call(this.node, info);
+        }
+      }
 
     };
 
@@ -145,31 +135,34 @@
 
       Polymer.Base.extend(DomApi.Mutation.prototype, {
         
-        addObserver: function(callback) {
-          this._ensureObserver();
-          return this._observers.push(callback);
-        },
-
         _ensureObserver: function() {
           if (!this._observer) {
             this._observer = 
-              new MutationObserver(this._notifyObservers.bind(this));
-            this._observer.observe(this.node, {childList: true});
+              new MutationObserver(this._notify.bind(this));
             // make sure to notify initial state...
-            this._mutationDebouncer = Polymer.Debounce(this._mutationDebouncer, 
+            this._debouncer = Polymer.Debounce(this._debouncer, 
               function() {
-                this._notifyObservers([{
+                this._notify([{
                   target: this.node, 
                   addedNodes: this.domApi.childNodes.slice()
                 }]);
               }
             );
-            this._mutationDebouncer.context = this;
-            Polymer.dom.addDebouncer(this._mutationDebouncer);
+            this._debouncer.context = this;
+            Polymer.dom.addDebouncer(this._debouncer);
+            this._preflush = this._flush.bind(this);
+            Polymer.dom.addPreflush(this._preflush);
           }
+          // note: doing this > 1x is a no-op
+          this._observer.observe(this.node, {childList: true});
         },
 
-        _notifyObservers: function(mxns) {
+        _cleanupObserver: function() {
+          this._observer.disconnect();
+          Polymer.dom.removePreflush(this._preflush);
+        },
+
+        _notify: function(mxns) {
           var info = {
             target: this.node,
             addedNodes: [],
@@ -188,26 +181,19 @@
             }
           });
           if (info.addedNodes.length || info.removedNodes.length) {
-            var o$ = this._observers;
-            for (var i=0, o; (i < o$.length) && (o=o$[i]); i++) {
-              o.call(null, info);
-            }
+            this._updateContentElements(info);
+            this._callListeners(info);
           }
         },
 
         _flush: function() {
-          this._notifyObservers(this._observer.takeRecords());
+          if (this._observer) {
+            this._notify(this._observer.takeRecords());
+          }
         }
 
       });
 
-      DomApi.prototype.flush = function() {
-        if (this._observer) {
-          this._observer._flush();
-        }
-        Polymer.dom.flush();
-      }
-
     }
 
 })();
diff --git a/src/lib/dom-api.html b/src/lib/dom-api.html
index a89ea1a6d6..906ca167dc 100644
--- a/src/lib/dom-api.html
+++ b/src/lib/dom-api.html
@@ -81,8 +81,8 @@
           addToComposedParent(container, node);
           nativeAppendChild.call(container, node);
         }
-        if (this._observer) {
-          this._observer.addNode(node);
+        if (this.observer) {
+          this.observer.addNode(node);
         }
         return node;
       },
@@ -118,8 +118,8 @@
           addToComposedParent(container, node, ref_node);
           nativeInsertBefore.call(container, node, ref_node);
         }
-        if (this._observer) {
-          this._observer.addNode(node);
+        if (this.observer) {
+          this.observer.addNode(node);
         }
         return node;
       },
@@ -150,8 +150,8 @@
             nativeRemoveChild.call(container, node);
           }
         }
-        if (this._observer) {
-          this._observer.removeNode(node);
+        if (this.observer) {
+          this.observer.removeNode(node);
         }
         return node;
       },
@@ -523,6 +523,21 @@
           }
         }
         return n;
+      },
+
+      observeNodes: function(callback) {
+        if (!this.observer) {
+          this.observer = this.node.localName === CONTENT ?
+            new DomApi.MutationContent(this) :
+            new DomApi.Mutation(this);
+        }
+        return this.observer.addListener.apply(this.observer, arguments);
+      },
+
+      unobserveNodes: function(handle) {
+        if (this.observer) {
+          this.observer.removeListener(handle);
+        }
       }
 
     };
diff --git a/src/mini/shady.html b/src/mini/shady.html
index 02cc11ed89..1529229346 100644
--- a/src/mini/shady.html
+++ b/src/mini/shady.html
@@ -13,6 +13,7 @@
 <link rel="import" href="../lib/dom-api-event.html">
 <link rel="import" href="../lib/dom-api-classlist.html">
 <link rel="import" href="../lib/dom-api-mutation.html">
+<link rel="import" href="../lib/dom-api-mutation-content.html">
 <script>
 
   (function() {
@@ -150,6 +151,18 @@
           this.shadyRoot._distributionClean = true;
           if (hasInsertionPoint(this.shadyRoot)) {
             this._composeTree();
+            // NOTE: send a signal to insertion points that we have distributed
+            // which informs effective children observers
+            notifyContentObservers(this.shadyRoot);
+            for (var i=0, c; i < this.shadyRoot._insertionPoints.length; i++) {
+              c = this.shadyRoot._insertionPoints[i];
+              if (hasDomApi(c)) {
+                var dc = Polymer.dom(c);
+                if (dc.observer) {
+                  dc.observer.notifyIfNeeded();
+                }
+              }
+            }
           } else {
             if (!this.shadyRoot._hasDistributed) {
               this.textContent = '';
@@ -164,10 +177,12 @@
               this._updateChildNodes(this, children);
             }
           }
+          // NOTE: send a signal to any Polymer.dom node observers
+          // to report the initial set of childNodes
           var hasDistributed = this.shadyRoot._hasDistributed;
           this.shadyRoot._hasDistributed = true;
-          if (!hasDistributed && hasDomApi(this) && Polymer.dom(this)._observer) {
-            Polymer.dom(this)._observer.addAllNodes();
+          if (!hasDistributed && hasDomApi(this) && Polymer.dom(this).observer) {
+            Polymer.dom(this).observer.addAllNodes();
           }
         }
       },
diff --git a/test/smoke/observeContent.html b/test/smoke/observeContent.html
new file mode 100644
index 0000000000..f6efae177d
--- /dev/null
+++ b/test/smoke/observeContent.html
@@ -0,0 +1,84 @@
+<!doctype html>
+<html>
+<head>
+
+  <title>observeContent</title>
+
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+
+  <script src="../../../webcomponentsjs/webcomponents-lite.js"></script>
+  <link rel="import" href="../../polymer.html">
+
+</head>
+<body>
+
+  <dom-module id='test-content'>
+    <template>
+      [<content id="ip"></content>]
+    </template>
+    <script>
+    (function() {
+      Polymer({
+        is:'test-content',
+        created: function() {
+        },
+        // _setupRoot: function() {
+        //   Polymer.Base._setupRoot.call(this);
+        //   Polymer.dom(this.$.ip).observeNodes(function(info) {
+        //     console.log('internal', info.changes[0]);
+        //   });
+        //   Polymer.dom(this.$.ip).observer.includeChanges = true;
+        // }
+      });
+    })();
+    </script>
+  </dom-module>
+
+  <dom-module id='test-static'>
+    <template>
+      My children do not render.
+    </template>
+    <script>
+      Polymer({
+        is:'test-static',
+        created: function() {
+        }
+      });
+    </script>
+  </dom-module>
+  
+  <test-content id="content">
+    <div>content A</div>
+    <div>content B</div>
+  </test-content>
+
+  <br><br>
+
+  <test-static id="stat"><div>static A</div><div>static B</div></test-static>
+
+  <script>
+  function obs(info) {
+    console.log('custom observer', info);
+  }
+
+  Polymer.dom(content.$.ip).observeNodes(function(info) {
+    console.log(info);
+  }, true);
+  Polymer.dom(content).flush();
+  Polymer.dom(stat).flush();
+  console.group('test dynamic');
+
+  var d = document.createElement('div');
+  d.id = 'foo';
+  d.innerHTML = 'Dynamic!';
+  Polymer.dom(content).flush();
+  Polymer.dom(content).appendChild(d);
+  Polymer.dom(content).flush();
+  // Polymer.dom(content).removeChild(d);
+  // Polymer.dom(content).flush();
+  console.groupEnd('test dynamic');
+  </script>
+
+</body>
+</html>
diff --git a/test/smoke/observeChildren.html b/test/smoke/observeNodes.html
similarity index 75%
rename from test/smoke/observeChildren.html
rename to test/smoke/observeNodes.html
index 0b9624f4b1..957a17cc6c 100644
--- a/test/smoke/observeChildren.html
+++ b/test/smoke/observeNodes.html
@@ -2,7 +2,7 @@
 <html>
 <head>
 
-  <title>observeChildren</title>
+  <title>observeNodes</title>
 
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
@@ -21,7 +21,7 @@
       Polymer({
         is:'test-content',
         created: function() {
-          Polymer.dom(this).observeChildren(function(info) {
+          Polymer.dom(this).observeNodes(function(info) {
             console.log('test-content', info);
           });
         }
@@ -37,7 +37,7 @@
       Polymer({
         is:'test-static',
         created: function() {
-          Polymer.dom(this).observeChildren(function(info) {
+          Polymer.dom(this).observeNodes(function(info) {
             console.log('test-static', info);
           });
         }
@@ -58,11 +58,11 @@
   Polymer.dom(content).flush();
   Polymer.dom(stat).flush();
   console.group('test dynamic');
-  function obs(mxns) {
-    console.log('custom observer', mxns);
+  function obs(info) {
+    console.log('custom observer', info);
   }
-  var hc = Polymer.dom(content).observeChildren(obs);
-  var hs = Polymer.dom(stat).observeChildren(obs);
+  var hc = Polymer.dom(content).observeNodes(obs);
+  var hs = Polymer.dom(stat).observeNodes(obs);
   
   var d = document.createElement('div');
   d.id = 'foo';
@@ -71,8 +71,8 @@
   Polymer.dom(stat).appendChild(d);
   Polymer.dom(content).flush();
   Polymer.dom(stat).flush();
-  Polymer.dom(content).unobserveChildren(hc);
-  Polymer.dom(stat).unobserveChildren(hs);
+  Polymer.dom(content).unobserveNodes(hc);
+  Polymer.dom(stat).unobserveNodes(hs);
   Polymer.dom(stat).removeChild(d);
   Polymer.dom(stat).flush();
   console.groupEnd('test dynamic');
diff --git a/test/smoke/observeReNodes.html b/test/smoke/observeReNodes.html
new file mode 100644
index 0000000000..336d04d9ab
--- /dev/null
+++ b/test/smoke/observeReNodes.html
@@ -0,0 +1,98 @@
+<!doctype html>
+<html>
+<head>
+
+  <title>observeReNodes</title>
+
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+
+  <script src="../../../webcomponentsjs/webcomponents-lite.js"></script>
+  <link rel="import" href="../../polymer.html">
+
+</head>
+<body>
+
+  <dom-module id='test-inner'>
+    <template>
+      ~<content></content>~
+    </template>
+    <script>
+      Polymer({
+        is:'test-inner',
+        ready: function() {
+          Polymer.dom(this).observeNodes(function(info) {
+            info.addedNodes.forEach(function(n) {
+              if (n.nodeType === Node.ELEMENT_NODE) {
+                console.log('added:', n.localName, n.textContent);
+              }
+            });
+            info.removedNodes.forEach(function(n) {
+              if (n.nodeType === Node.ELEMENT_NODE) {
+                console.log('removed:', n.localName, n.textContent);
+              }
+            });
+          });
+        }
+      });
+    </script>
+  </dom-module>
+
+  <dom-module id='test-content'>
+    <template>
+      <test-inner id="inner">[<content id="ip"></content>]</test-inner>
+    </template>
+    <script>
+    (function() {
+      Polymer({
+        is:'test-content'
+      });
+    })();
+    </script>
+  </dom-module>
+
+  <test-content id="content">
+    <div>content A</div>
+    <div>content B</div>
+  </test-content>
+
+  <br><br>
+
+  <script>
+  
+  function makeNode(text) {
+    var d = document.createElement('div');
+    d.textContent = text;;
+    return d;
+  }
+
+
+  Polymer.dom.flush();
+  
+  // setTimeout(function() {
+    console.group('test dynamic');
+    var d = makeNode('dynamic!');
+    Polymer.dom.flush();
+    Polymer.dom(content).appendChild(d);
+    Polymer.dom.flush();
+    Polymer.dom(content).removeChild(d);
+    Polymer.dom.flush();
+    Polymer.dom(content).appendChild(makeNode('1'));
+    Polymer.dom.flush();
+    Polymer.dom(content.$.inner).appendChild(makeNode('2'));
+    Polymer.dom.flush();
+    Polymer.dom(content).insertBefore(makeNode('-1'), Polymer.dom(content).firstChild);
+    Polymer.dom.flush();
+    Polymer.dom(content.$.inner).insertBefore(makeNode('-2'), Polymer.dom(content.$.inner).firstChild);
+    Polymer.dom.flush();
+    Polymer.dom(content.$.inner).removeChild(Polymer.dom(content.$.inner).firstChild);
+    Polymer.dom(content.$.inner).removeChild(Polymer.dom(content.$.inner).lastChild);
+    Polymer.dom(content).removeChild(Polymer.dom(content).firstChild);
+    Polymer.dom(content).removeChild(Polymer.dom(content).lastChild);
+    Polymer.dom.flush();
+    console.groupEnd('test dynamic');
+  // }, 1000);
+  </script>
+
+</body>
+</html>