Well you had better grab a copy quick! Microsoft has extended the beta until Feb 10th, however it won’t go further than that.

If you do not start your download by February 10th, you will loose the chance.

http://technet.microsoft.com/en-us/windows/dd353205.aspx

This also means you have to register before the 10th, however as long as you start your download before then, you can take up to two more days to finish the download. After that, the download will be gone for good.

Product keys will continue to be available after this point, however without the download, what are you going to use it on?

-Michael