So if you ain’t started yet then I suggest you get cracking on that download!
From Brandon on the Windows team blog
February 10th: Starting at 12am Pacific Time, no new downloads will be available. If you have already begun downloading the Windows 7 Beta, you have until Feb. 12th to complete the download.
February 12th: Starting at 9am Pacific Time all downloads will no longer be available for the Windows 7 Beta. If you have not finished your download, you will be unable to do so.
After February 12th, folks will still be able to register for product keys for the Windows 7 Beta.
The above schedule does *not* apply to TechNet and MSDN Subscribers.