I get asked a lot, how does the new HyperV compare to vSphere especially since VMworld just ended.  Well now we have a document that provides spec by spec comparisons of vSphere and HyperV.  This doc is up to date with all of the announcements made in the past two weeks on both Windows Server 2012 and VMware vSphere 5.1:  http://aka.ms/hypervcomparedtovsphere   Also, here's a free ebook that's a good intro to Windows Server 2012:  http://aka.ms/hypervintroebook