If you have been following the W3C WebRTC spec and looking at the Chrome implementation, you will have noticed that our implementation was not spec compliant.
RTCPeerConnection is replacing PeerConnection00. RTCPeerConnection is the API you will find in the upcoming stable version of Chrome, and the last major API change before we go to a public stable release.
These changes signify breaking current applications. We do not take this lightly. It is the unfortunate consequence of being at the forefront and of using the Chrome Canary and Dev channels to help the community iterate on the WebRTC API.
As Chrome 23 hits the beta channel, we will move the older, deprecated PeerConnection00 behind a flag, --enable-deprecated-peerconnection, and remove it completely thereafter.
Once WebRTC goes into the stable channel of Chrome, API changes will be done with a longer, smoother transition period.