For starters, everyone knows Microsoft is keen to move past the PR train wreck that is Vista. And the beta has received such fawning praise from the media, Microsoft no doubt wants to capitalize on all that goodwill.
But I think the best evidence is the beta's expiration date: August 1, 2009. Microsoft would be cuh-razy to leave happy beta-testers without a working version of the OS. Thus, my bet is we'll see Windows 7 on store shelves by July.
What do you think? Vote in our poll, then hit the Comments to share your Windows 7 drop-date predictions.