Less the CEO than the culture...
If you look at the things people who were inside Microsoft during it's many failed phone/iPod/whatever mini-gadget is cool now debacles are saying it's clear that the biggest problems inside Microsoft is the corporate climate, rampant territorialism and crippling factionalism. It is true that the CEO sets the tone, but simply removing him won't change anything unless they shake up the leadership of all the departments and divisions, then re-organise them, too.