So I think your missing the point. MS & VMware are working together and it is well known that you can't DRS a windows cluster. It looks like whoever wrote the vmware papers didn't talk to the support guys.
In years gone by, MS and VMware would have and did fight each other when it came to supporting various configurations, but now with SVVP they are actually working together and Windows 2008 R2 is fully supported on ESX except then you cluster the OS.
At the end of the day when you design and install a solution, the important thing for a customer is vendor support and that is what SVVP provides. The Exchange team don't really care what virtual platform you use (of course they want you to use Hyper-v) they really just want you to use Exchange and not another product.
They also want your design to be properly configured and I think this is what prompted this blog post. <end of rant>
Thanks Jim for the clarification.
Microsoft
