I can't buy either of those arguments. There's a big difference in compatability between Mac, Linux and PC.
MS are a huge company, I can't see them going into administration.
They are split into different sectors though, so they could see one being scrapped (here it's windows), and carry on with the rest of the company. But, if it was to happen, Microsoft would loose a lot of money from it, and probably go into administration later on in the decade or so.
Brandon