On April Microsoft published a Support article about products it won’t support on Virtual Server 2005 Standard Edition:
- Microsoft Speech Server
Speech Server requires telephony hardware not available in a virtualized hardware environment, and thus Speech Server is not supported when run within Virtual Server. - Microsoft Certificate Server
Certificate Server is supported starting with Windows Server 2003, Standard Edition SP1 and Windows Server 2003, Enterprise Edition SP1 as the host and guest operating systems. - Microsoft ISA Server
ISA Server is currently not supported running within Microsoft Virtual Server. Support for ISA Server within Virtual Server is expected in a future release. - Microsoft Exchange Server
Exchange is currently not supported running within Microsoft Virtual Server. Exchange will be supported within Virtual Server starting with Exchange 2003 Service Pack 2 and subsequent releases. - Microsoft SharePoint Portal Server
SharePoint Portal Server is currently not supported running within Virtual Server. Support for SharePoint Portal Server within Virtual Server is expected in a future release.
Please notes that these limitations don’t refer to the just released Virtual Server 2005 R2. So I strongly suggest you to monitor this article for updates.
Credits to Mauro Cardarelli. Thanks to John for notifying me.