Windows Server 2012 build 8102

Windows Server 2012 build 8102 is the official Developer Preview build of Windows Server 2012. This build includes many features from Windows 8 RTM, including the Start screen, Metro interface, and Charms.

Timebomb update
While this build was originally set to expire in 2012-03-11, but Microsoft has released KB2671501 for both Windows 8 and Server 8 Developer Preview to extend the expiration date to 2013-01-15.