Vaguely ironic?
MS releases WS2k7 with Hyper-V to manufacturing around the same time Ms Greene departs and Paul Maritz (ex-MS), now VMware CEO...
Market sentiment/impact: depends on what Paul M has to say as to which way the company will be going under his leadership. Early adopters are probably dead happy with VMware, from functionality and maybe 'its not MS' points of view...
Hyper-V arriving embeds virtualisation in the MS furniture... future suggests you get it anyway even it you may not want or need it. Added complexity may put some off it for now, re:support, but tools are always being developed.
http://blogs.zdnet.com/microsoft/?p=1458
Interesting times ahead...