In this video Interview, Joe Schurman (MVP) shares some of the things they are doing around testing Office Communications Server in a Virtualized environment. Please understand that this is not an officially supported configuration from Microsoft, but at least you can see that there are folks doing testing of these different work loads. Joe also discusses a few other things with MS Research as well, but you'll need to watch the video.
To activate the Silverlight control, click on the video. To go full screen, double click the video. Enjoy.