Well, this is the first time in a long time that I've blogged about cumulative updates for two different versions of SQL Server on the same day. Yesterday Microsoft released a cumulative update for SQL Server 2008 SP1 (bringing you to 10.0.2775), and a corresponding cumulative update for SQL Server 2008 R2 RTM (bringing you from 10.50.1600 to 10.50.1702). You can read more about these updates here:
Note that the cumulative update for SQL Server 2008 R2 is merely a rollup of the updates found in cumulative updates 5, 6 and 7 for 2008 SP1 – it does not include several of the fixes from CU #8 for 2008 SP1. I would expect to see a continued pattern of bugs relevant to both versions being fixed in one branch, and not rolled into the other until the subsequent update (and where it appears first will depend on where it was discovered).