UPDATE 2013-08-23: 2008 R2 SP2 CU #8 is now available; details below.

UPDATE 2013-08-14: I had originally posted about SP1 CU #14, and was sure SP2 CU #8 was coming in shortly behind it, but it turns out that CU #14 has been pulled from general availability and has been converted to an on-demand hotfix update. Some people suggested this indicates some kind of quality or regression issue with the cumulative update itself, but if that were the case, it would have been pulled entirely instead of just getting a new label. This has to do with the fact that SP1 support ends on October 8th; I don't believe CU #14 will ever formally come to be. And just as well – you should be on the SP2 branch anyway.

Previous post, for posterity: 

Microsoft has released a cumulative update for SQL Server 2008 R2 SP1 (and I am leaving a placeholder for the forthcoming update for SP2).

SQL Server 2008 R2 Service Pack 1 Cumulative Update # 14

• KB Article: KB #2868244
• 3 fixes listed at time of publication
• Build number is 10.50.2881
• Relevant for @@VERSION 10.50.2500 through 10.50.2880

SQL Server 2008 R2 Service Pack 2 Cumulative Update # 8

• KB Article: KB #2871401
• 13 fixes listed at time of publication
• Build number is 10.50.4290
• Relevant for @@VERSION 10.50.4000 through 10.50.4289

My usual disclaimer: these updates are NOT for SQL Server 2008 (or SQL Server 2012). Only apply to systems where SELECT @@VERSION returns 10.50.xxxx, where xxxx is >= 2500. If xxxx < 2500, you need to start thinking about getting off the RTM branch. And based on the number of fixes making it into the SP2 updates, and the fact that support for SP1 ends on October 8, 2013, you might consider abandoning SP1, too, if possible…