Quoting from Bink.nu:
Today Microsoft changed its support towards Microsoft software running on VMware serveres (and virtual software in general).
Untill yesterday if you had a Microsoft Premier Support contract and you had a problem with a Windows server running in a virtual machine running on VMware GSX or ESX server, the support engineer would not help you. In those cases you had to re produce the problem on physical hardware, even with Premier Support contract.
Today that has changed, a bit, read carefully:
For Microsoft customers who have a Premier-level support agreement, Microsoft will use commercially reasonable efforts to investigate potential issues with Microsoft software running in conjunction with non-Microsoft hardware virtualization software. As part of that investigation, Microsoft may require the issue to be reproduced independently from the non-Microsoft hardware virtualization software. Where issues are confirmed to be unrelated to the non-Microsoft hardware virtualization software, Microsoft will support its software in a manner that is consistent with support provided when that software is not running in conjunction with non-Microsoft hardware virtualization software.
Well it’s better then before,
Non-premier customers don’t get this support:
Microsoft does not test or support Microsoft software running in conjunction with non-Microsoft hardware virtualization software. For Microsoft customers who do not have a Premier-level support agreement, Microsoft will require the issue to be reproduced independently from the non-Microsoft hardware virtualization software. Where the issue is confirmed to be unrelated to the non-Microsoft hardware virtualization software, Microsoft will support its software in a manner that is consistent with support provided when that software is not running in conjunction with non-Microsoft hardware virtualization software.
Complete KB: http://support.microsoft.com/kb/897615