If you have an HPC Pack 2008 R2-based cluster that you have not yet upgraded to SP1 - Why?

HPC Pack service packs provide the most current set of fixes to improve stability, reliability, and performance. This particular service pack also included some new features, such as the ability to run certain workloads in Azure (http://technet.microsoft.com/en-us/library/gg481751(WS.10).aspx)  

Let us know your thoughts over on our discussion forum: http://social.microsoft.com/Forums/en/windowshpcitpros/thread/205ef11d-d71a-46cc-830d-234b1436c1df