List of Cluster Hotfixes for Windows Server 2008 R2

http://social.technet.microsoft.com/wiki/contents/articles/2008.list-of-cluster-hotfixes-for-windows-server-2008-r2.aspx
•2687741 — A hotfix that improves the performance of the "AlwaysOn Availability Group" feature in SQL Server 2012 is available for Windows Server 2008 R2