Nice thing about the MP containing these two Reports (Microsoft.Windows.Server.Reports.mp) is that it works perfectly together with the previous version of the Server OS MP! Tried it in one of mine SCOM R2 CU#5 test environment and the Report MP was imported quickly, Reports uploaded to SSRS as well and they work like a charm.
Of course, I tried this only in a SCOM R2 test environment so try it yourself in a test environment as well before moving to production but until now everything looks great!
And again, I tested it only on SQL Server 2008. I have heard rumors the Reports don’t work with SQL Server 2005.