Windows 7 Beta ISO leaked on torrent trackers
The ISO appears to contain the Windows 7 M1 build (7000) highlighted by Paul Thurrott on SuperSite. So far the new build seems to perform slightly better than 6801, and memory usage has been improved. A number of previously hidden features - like the iconized task bar - are also now active.
Before comments start asking why there's no link to the file, it's because this is something that we're not supposed to have yet. If you want to get your hands on it, check your favorite torrent search site. Also keep in mind that this is a leak, and there's always the possibility that the ISO has been tampered with.