<Update> I have include information on how to upgrade from R2 RC to R2 RTM.
Not much has changed when upgrading from Operations Manager 2007 SP1 to R2 or deploying a fresh installation of Operations Manager 2007 R2. However, I do want to take the opportunity to point out few of the changes.
Changes to supported platforms
Operations Manager R2 now supports OM database roles running on SQL 2008 with SP1. Please be sure install SP1 of SQL 2008 before beginning your R2 install or upgrade. Our Prerequisite checker detects for SQL 2008 SP1and will block until it is found. Note: We still continue to support SQL 2005 with SP1 or higher.