Tough sell...
....unless you're purely virtualizing a set of recent-ish Windows releases, and even then...
From an OS support point of view we have, on one hand, a very well established player in virtualization, with excellent tools and support for Windows 95 to v7, Windows Server, Solaris 8-10, endless Linux variants including SuSE, RedHat and Ubuntu, a number of BSD flavours and similar including Apple OS-X Server and other Unices such as NetWare.
On the other hand, Hyper-V with support for Windows XP to v7, Windows Server 2000-2008, SuSE and RedHat.
Quite a difference, and one that might be relevant to potential customers....unless, of course, the announcement is support for HP-UX on Hyper-V !! Wohooooooooooo - that'll slay 'em ;)