If you are interested in how Microsoft has changed Hyper-V in Windows Server 2012, you need to watch todays TechEd US sessions from Jeff Woolsey.
http://channel9.msdn.com/Events/TechEd/NorthAmerica/2012/VIR308
http://channel9.msdn.com/Events/TechEd/NorthAmerica/2012/VIR309
I think these change are a real game changer in the Virtualization Landscape, lookout VMware.