Saw a message from Nishtha Soni today about the support for SQL 2008 R2 SP1 for SCOM: I will paste it below. A big thanks for the message from Nishtha!!
System Center Operations Manager 2007 R2 now supports SQL Server 2008 R2 SP1. Note: We will have the Supported Configuration posted in the next few weeks to make this more official, but feel free to go ahead and install it.
Nishtha Soni | Program Manager