Although Windows Server 2008 is not released in public domain yet, Netcraft reports that there are already around 2,600 sites running on Windows Server 2008 on the Internet and some of these sites are at Microsoft itself. The main site of Microsoft, Microsoft.com is now running on Windows Server 2008 and IIS version 7. Windows Server 2008 is due to be released in the second half of 2007 though.
» Source [Netcraft]