I spend almost all of my time in firefox, emacs and a few other programs, which are the same on every platform. It really doesn't make much of a difference to me what desktop OS I use as long as it's cheap and it works with my hardware. I use Ubuntu on an HTPC because it's free and it (usually) works. I can't imagine what MS or Apple could do to improve on free + works.

To me Linux is a lot closer now than it was in the past because you can pop a Ubuntu CD into a computer and 9 times out of time it you have a working computer with sound and everything half an hour later. 7 years ago, when I first installed linux, that would have been more like 1 time out of 10.