Microsoft has released SQL Server 2008 R2 Service Pack 2 Cumulative Update 10, which is build 10.50.4297. This Cumulative Update has fifteen fixes in the public fix list.
This Cumulative Update is only for SQL Server 2008 R2 Service Pack 2 (which is the only supported Service Pack for SQL Server 2008 R2).
If you are on SQL Server 2008 R2, you really should be on Service Pack 2 by now.
Glenn Berry's SQL Server Performance 