A SAP on Hyper-V paper was just brought to my attention. It has a very good overview of Hyper-V and how it benefits SAP,  The document focuses on getting SAP running well in Hyper-V and has lots of great technical information.  One thing I wish the paper had was solid performance data showing how the suggestions help improve performance and what the overhead is when going from physical to virtual.  Even without that the paper is a good read.