are now available for download.  No more calling up PSS or Microsoft Services requesting the hotfix from KB 900076 http://support.microsoft.com/?kbid=900076

Once you install these in the VM guests you will notice a performance increase, most noticeably if you are running Server 2003 SP1 (or R2)

This download will update the VM Additions included with the original Virtual Server 2005 Release (13.206) to the version included with Virtual Server 2005 R2 (13.552). This version includes all of the performance improvements for running Window Server 2003 SP1 or R2 as a guest within a Virtual Server virtual machine.

Virtual Server 2005 R2 VM Additions

http://www.microsoft.com/downloads/details.aspx?FamilyId=A963433C-193B-41AC-AF6E-AB7AB2DB8541&displaylang=en