Wow that was fast. It was only a couple of weeks ago that VMware joined the Microsoft Software Virtualization Validation Program (SVVP) and now ESX 3.5 Update 2 has been offically certified under that program. This means that now ESX and Hyper-V are supported virtualization platforms for running Microsoft applications. This removes a big issue that many customers had regarding support for Microsoft apps like Exchange, SQL Server, and SharePoint when running on VMware ESX. Check out the Microsoft Virtualization Team Blog and Scott Lowe's blog for some some additional details.
Todd
Virtualization on the Edge