I had applied updates to my newly built 2008R2 wsus server and it broke it. The update failed to install and kept wanted to restart the server.
None of the suggestions on any forums resolved the issue. Finally, open a support ticket with Microsoft. They said, while I waited for a WSUS tech, to install KB2734608.
I installed this update, reboot the server and life is good.
Why this updated isn't posted for this issue with all the activity going around, can't imagine.
cheers