"Feast your eyes on the freshest high-quality leaked screenshots and video of Windows 7 Milestone 1! Windows 7 is of course the next edition of Windows, designed as a successor of Windows Vista. And since Vista was no. 6, and under Steven Sinofsky, Senior Vice President, Windows and Windows Live Engineering Group, Microsoft is no longer referencing software under development by codenames, but by product numbers, the next iteration of the operating system naturally became Windows 7. At this point in time, Microsoft is also making headway with the building of the platform's early stages."
Source: Full Article @ Softpedia
Related: Whatever You Do, Do Not Download Windows 7 Via Torrent Sites - January 29, 2008
You can find the screenshot and the short youtube clip below.