This is a temporarily solution to extract private keys from the old key store on the current olympic test net. This will only work for clients that have old keys (geth <v0.9.20).
Usage:
gethkey <address> <export_file>
Installation:
Installation assumes you have godep installed
git clone https://github.com/ethereum/gethkey.git
cd gethkey
godep go install