Info from github:

https://github.com/bitcoin/bitcoin/pull/574

"gavinandresen merged 5 commits into bitcoin:master from sipa:dumpprivkey 9 days ago

sipa (re)opened this pull request October 07, 2011
Dumpprivkey

Introduces three new RPC calls:
* dumpprivkey: retrieve the private key corresponding to an address
* importprivkey: add a private key to your wallet
* removeprivkey: delete a private key from your wallet" - It isn't active yet.

I am a fan of this pull request! One requirement of greencoin was inspired by this...

Congratulation sipa, jgarzik and gavinandresen!