Yeah, Sinofsky runs windows (cash cow #1) and used to run Office (cash cow #2) which still (allegedly) has a lot of loyalty to him. With these two divisions supporting him he is probably the strongest internal candidate.
That was my initial thought too, but I think everyone will benefit if he'll stick to his own guns and keep turning products around (think Office 2007, Windows 7 and Internet Explorer 9).
Sinofsky is really good at running Windows & Office, but is he the right guy to successfully expand beyond that? MS is getting its butt kicked in mobile, social, and consumer electronics, all of which Sinofsky doesn't have direct experience.
Gates didn't have direct experience in any of the areas Microsoft ended up dominating. In the end, the CEO's role is more visionary than mentor. His job is to guide, not to teach. A good CEO can make smart choices about technologies with which he's unfamiliar, if he has a vision in mind. Compare Sculley and Jobs in their approach to Apple: neither was technologically gifted, but Sculley relied on the engineers to dictate direction, whereas Jobs (mk II) dictated direction to the engineers. The point is that a CEO need not be Gates: he need not have an intimate knowledge of the technology, so long as he has a clear and accurate vision of its future.
