I had to check the URL for Port 25 in the last post (is it technet ... or MSDN ? its http://port25.TECHNET.com), and in doing so I spotted a post I'd missed from a few days ago.
The Virtual Machine Additions for Linux 2.0 download is now available. This is to provide better support for qualified distributions of Linux running on Virtual Server 2005. I understand that work is going on for the equivalent software for Windows Server Virtualization, but no-one's ready to share a date for when these will be available even as a beta.