Microsoft are currently working hard towards the Release Candidate of Windows 7. Currently the only official build available to testers and the general public is build 7000 but we have learned that 7022 has leaked to the internet today.
According to a Russian torrent site it was leaked by "friendly" Microsoft Ukraine individuals. It's not likely that the build contains any of the UAC changes Microsoft has recently promised. The build is Build 7022.winmain.090115-1850 which indicates it was built nearly a month ago. Some Microsoft employees have twittered recently that they were "installing build 7034" so the company is clearly pushing ahead with the builds ready for the upcoming Release Candidate.