Windows 7 Beta is now available to the public for testing before the final release which is due in late 2009 ( as of now the expiring date for the beta is Aug,2009 that makes it obvious final version release date) . It can be downloaded from Microsoft technet site (Updated links added for Beta download) but as of now the servers are too busy and are unable to handle the load.
The links will be updated soon as and when it becomes available.
