FYI --
MS began distributing SP1 on Tuesday, March 19, 2013. I noticed on Wednesday that all my WIN7 computers had quietly been upgraded to SP1. So, I decided to check my WHS 2011 as well. (You do that by clicking on Control Panel then on System.)
WHS 2011 had also quietly upgraded to SP1.
I have noticed no ill affects due to the SP1 update.