Adding Asynchronously loaded image to a custom marker

[rodericj]

What would be the recommended way to add a custom marker that has a UIImage which is loaded from an asynchronous (web/cache call) thread. I'm toying around with subclassing MGLAnnotationImage as well as adding a category similar to https://github.com/AFNetworking/AFNetworking/blob/master/UIKit%2BAFNetworking/UIImageView%2BAFNetworking.h. It becomes a bit c-like as I'm diving into CALayer which I feel may not be the most appropriate path.

Just wondering what the community recommends for something like this.