. On August 1, 2009 if you are still on the Windows 7 beta, your license will expire and the non-genuine experience will be triggered. Your wallpaper will be removed and "This copy of Windows is not genuine" will be displayed in the lower right corner above the taskbar.
Bi-hourly shutdowns of this build will begin on July 1, 2009.
Yup, the timetable for the Beta expiring is correct. The Release Candidate (and later builds) expires on June 1st of 2010. They start doing two hour reboots starting March 1st of 2010. For those of you who need to get the RC, you should do it quickly before your beta times out. You can pick up the RC and your free license from TechNet here: Windows 7 RC | Support, Deployment, Resources
The evaluation offer is open until August 15th, so get it before then. The commercial release of Windows 7 is due out on October 22nd.
Kurtis Whittington - Microsoft Windows Client Team