Before I begin let me clarify a few points so you are aware of the context of this post.
1) I currently work for a Microsoft Gold Partner, been contracted to Microsoft (through my employer) and spoken at TechEd.
2) Before that I worked for company which used almost solely open source software and developed software for that. I also did work with the Shuttleworth foundation at the linux days event.
So I have been on both sides of the fence, now on to the content...
Well I am not going into the free part, since until I can live without money making everything free doesn't help and there is many people in the traditional OSS community which do make money (RedHat, Novell, many linux contributors etc...) so I guess I am not alone in this view.
But many people bring up the open source side, which makes less sense to me. Microsoft does have this shared source thingy which is some special license for special people, but that doesn't fit with true OSS where anyone can access it so I'm not including it. Microsoft has Port25 (there public front for their internal open source lab) which has some interesting information, but not really pushing OSS. There are also a few "sponsored" projects on SourceForge and the now defunct CodePlex. Neither of these push OSS as part of major projects. So while benefical aren't big enough.
So what is it that doesn't make sense to me? Simple, the .Net framework is completely open source. All of the .Net assemblies are in source code (IL) all the time and thanks to reflection can be transformed into a convient language of choice of the viewer. Since .Net is the big push from Microsoft the new core of their systems will be open source. This can be seen currently with their applications built on top of it, like Microsoft CRM which has all their assemblies in .Net and can all be opened and viewed. Microsoft CCF is even further advanced with it including some applications in .Net (like the admin console) but the bulk is available in direct source code. BTW Neither are obfuscated in anyway, so there is no attempt to close this source.
Agreed that the core big money makers (Windows, Office etc...) are still closed source, but how much of that is legacy versus how much is based on the choice of language tool (C++ Win32 vs Dot Net) and how much of that is specific plans to close off the source I can not say and no one outside the core executive at Microsoft could say, but the argument that Microsoft doesn't get it, is just wrong. They get it and probebly more than most of the zealots mentioned earlier since they have figured out to use it strategically.