Linux (gasp) isn't the dirty word within Microsoft it might once have been. There seems to have been some surprise that we're providing support for running Linux under Virtual Server 2005 R2. The only thing I've found a little surprising is the amount of media attention this has got. By no means are Microsoft suddenly suggesting people use Linux instead of Windows, but it is a clear recognition of the realities of modern business.
Windows isn't going anywhere anytime soon. Neither is Linux. A huge number of people run systems taking advantage of the best features from both, and that's something we need to recognise and support to provide the best customer experience possible. And it all makes good business sense - people aren't going to run a virtualization solution that doesn't support the operating systems they need to use. Tristan Louis has an interesting (independent) article on this move by Microsoft and what it means
If you're interested in what Microsoft can offer in terms of interoperability, there's a wealth of resource available at the Interoperability and Migration Centre. This includes free access to a download of Windows Services for UNIX 3.5.
Talking of operating systems popping up in unexpected places, Apple endorsing XP on a Mac? Didn't see that coming :-)