Microsoft recently announced the release of Service Pack 1 for both Server 2008 R2 and Windows 7.
SP1 is available for download with your MSDN subscription now, and general availability on Feb 22.
Documentation on SP1, what it includes, and changes to each OS is available here:
I have been running SP1 on my 2008 R2 servers in my lab environment for a while now, along with SP1 on all my Win7 desktops and VM’s.
Relative to OpsMgr – this is a very important Service Pack to evaluate – as this includes the WMI Leak Hotfix that is critical for your OpsMgr monitored agents and servers running on Windows 2008 R2 RTM. If you aren't planning on deploying SP1 to your 2008R2 agent monitored machines soon, then strongly consider rapid deployment of the WMI leak hotfix in the article above.