The Cumulative update package 14 for SQL Server 2008 R2 (Build 10.50.1817.0) is available:

Cumulative update package 14 for SQL Server 2008 R2

And here you can get the whole information of builds that were released after SQL Server 2008 R2 was released:

http://support.microsoft.com/kb/981356/

The Cumulative update package 7 for SQL Server 2008 R2 Service Pack 1(Build 10.50.2817.0) is available:

Cumulative update package 7 for SQL Server 2008 R2 Service Pack 1

And here you can get the whole information of builds that were released after SQL Server 2008 R2 Service Pac k 1 was released:

http://support.microsoft.com/kb/981356/