The shutdown of general availability for the Windows 7 Beta will occur in 3 phases over the course of the next few weeks:
Product keys for the Windows 7 Beta will continue to be available. So if you have the Windows 7 Beta but didn’t get a product key you will be able to do so even after February 12th.
Links:
[1] http://pulse.veltsos.com/category/it/it-general
[2] http://pulse.veltsos.com/category/it/software/software/os/microsoft
[3] http://pulse.veltsos.com/category/it/software
[4] http://windowsteamblog.com/blogs/windows7/archive/2009/01/23/general-availability-for-the-windows-7-beta-to-end.aspx