Hyper-V completes Common Criteria Certification, achieves EAL4+

"Last week Windows Server 2008 R2 completed the Common Criteria (CC) certification process and achieved Evaluation Assurance Level 4 with augmentation (EAL4+). This certification also includes Hyper-V. "

More here: http://blogs.msdn.com/b/virtual_pc_guy/archive/2011/05/04/common-criteria-validation-for-hyper-v-in-windows-server-2008-r2.aspx