While the validation of SAP applications on Windows Server 2008 R2 currently still goes on. It's now officially supported by SAP to use new Hyper-V implementation in 2008 R2 for SAP installations in Virtual Machines (VM's have to be on Server 2008 or Server 2003). Support statemenst of SAP can be found on SDN or in SAP note 1409608. Advantage to use R2 as Hyper-V Server especially for SAP apps is: Live Migration is available; Processor Compatibility enables migrations between older and newer server (different chipsets); Support for more logical processors on the parent, 64 processors vs. 32 in Windows Server 2008; Support for Second Level Address Translation; Enhancements in the network configurations of VM's like Jumbo-Frames, TCP-Offload for iSCSI; Dynamic Add/Remove of storage in a VM; Performance improvements in network, storage and memory management of VM's; Support of Core Parking in the parent improves the energy efficiency. Capabilities of Hyper-V in R2 makes it very attractive for SAP installations at an excellent price point.