According to a article in CRN, Micros0ft is working with Sun to make sure that their virtualization will be compatible. This means that if I purchase a Sun server with Solaris, It should, emphasis on *should* be able to run MS Server.
Do I want this? Sure why not. I like running multiple operating systems to see what I like the best. They all have benefits and flaws. For instance MS Windows is great for the business world. i.e. applications. I love Mac OS X for it's beauty and simplicity. It is the perfect OS and system for home users.
If I want to code, I then use Linux/UNIX depending on what platform I need to try to write or debug software on. I'm no expert programmer, but can read and write some C, HTML (not a programming language) PERL and Assembly X86.
With Web 2.0 taking off. A popular buzzword. What it really is is services using AJAX. Think of applications on the web to use. Google Apps comes to mind, Facebook and Myspace.
To sum this up I think it is a smart move for Microsoft. After all Novell has Xensource.