You are right on point.
I wouldn't be surprised if they were going to soak up all the money from the impending Vista release, then announce that they are cutting Windows loose.
"We are spinning off our Windows subsidiary."
It is quite possible Windows will someday be available for free download from Microsoft servers, just as they have done with their Express versions of Visual C#, C++, Basic, Web, etc.. They would continue to charge for support, advanced versions of programming languages, SQL servers, and web servers and services. The Windows OS could be the free hook to draw you into the MS world.