Microsoft makes standalone Hyper-V R2 server available for download | All about Microsoft | ZDNet.com

Hyper-V R2 is a standalone virtualization server targeted at small- and mid-sized business customers. The R2 release, an update to the Hyper-V Server 2008 product, adds support for live migration and high availability, meaning, in this case, automatic restart on another node without user intervention.

And its free too. I do know of one local IT team using the earlier version and saving a lot of $$$ in VMWare licence fees. It's an interesting time when commercial vendors provide quality software for free.