To echo what some others have already said, I don't see how coming back to Microsoft could be more personally satisfying for Gates than what he's doing now. Sure, it would probably feel pretty nice if he could right the ship and get lauded in the same way Jobs has been as of late. Let's be honest though: the stuff Gates is doing today is way more important than any of the things Jobs did over the last decade. We can…
http://www.gatesfoundation.org/annual-letter/2011/Pages/home...
Without considering it, one might think that with billions of dollars, accomplishing any task should be a rather straightforward issue. Reading his letters provides a view on how much work and how big their challenges are.