Whats the suprise here, MS will always go where the money is. This is a point I discussed with a friend a couple of years ago. The USA DOD has lots of cash for software, so MS will eventually write software for the platform that is preferred. If this is a Sun product then that is what they will target, if it is Linux then expect Word for Linux.
I would expect MS to go the linux route then they can target Sun, Corel, IBM/Lotus and StarDivision all in one go !