We often get the question by customers on how to find newly released hotfixes for Cluster. We have 2 Wiki pages that will make life easier for you when looking for hotfixes for Windows Server 2008 R2 Cluster. You can also setup an RSS Subscription to the Wiki page so you can the updated Wiki page in your favorite RSS app or Outlook.
List of Cluster Hotfixes for Windows Server 2008 R2:
List of Failover Cluster Packages Updated After the Release of Windows Server 2008 R2 Service Pack 1 (SP1):