It was rather overshadowed by the Windows 7 RC, but last week Microsoft also made available the release candidate for Windows Server 2008 R2:
As many of you know, Windows Server 2008 R2 Release Candidate (RC) is made available today to MSDN and TechNet subscribers, with broader availability from Microsoft.com on May 5th. As our final broad test milestone before RTM, this really is the best chance for you to download Windows Server 2008 R2 and put it through its paces while we continue our march to RTM.
There’s more on the new R2 management features by following the link and you can also check the full pitch on Windows Server 2008 R2, but bear in mind that the R2 means it is an interim release between major Windows Server releases, so don’t expect earth shattering enhancements. The biggies to my mind are the improved management and the new release of Hyper-V virtualization.