I, personally, want Microsoft to succeed. Not so I can go back to a Windows computer (neverrrr) but so I can buy whatever they create after Windows.
Not to mention, (solid) competition drives innovation. To me, that's the most important reason to root for Microsoft's success.
Replacing Steve Jobs would be much tougher assignment.
Don't forget to deactivate Ballmer's badge and get some fresh air into the boardrooms :)
It's a less than great choice because Microsoft's approach to finding The Next Big Consumer-oriented Thing has been wasteful, yet too conservative. Too conservative in terms of looking beyond Windows and PCs, but too lavish in spending on attempts that flop. Maybe Nadella will be more careful about splashing out lots of money building too many Surface RTs. But that's only half the problem.
This could well be a strong sign that Microsoft future focus would be hardly in consumer market, given the choice of CEO.
Really, a lot like what seemed to happen with Bush and Obama.