Well, not all of OCS, but for specific server roles. The roles include: front-end, back-end SQL Server 2008 64-bit; group chat channel; group chat compliance; archiving; monitoring (CDR only); and edge access. The roles that are not supported are: audio/video/web conferencing servers, audio/video/web edge conferencing servers, dial-in conferencing, Communicator Web Access, enterprise voice, or Remote Call Control “may not be deployed as part of the virtualized pool.”
In my recent research on cost savings best practices, interviewees consistently mentioned server consolidation. Virtualization goes hand-in-hand with server consolidation efforts. However, communications technologies – in general – are difficult to run virtualized because of high server transactional costs that lead to high CPU utilization, heavy disk IO, and large quantities of attached data. As a result, support for virtualization of communications technologies has lagged behind other server applications. IBM has done well in this area with support for both Notes and Sametime available.
A whitepaper from Microsoft is available that details the architecture, methodology, and performance.