I could see him doing it, but I don't see him actually sorting anything out. His last years were not stellar. He did a fantastic job building the company, but I don't think he's the right person to rebuild it.
There's one MS higher-up who I could see actually pulling it off: J Allard. If the future of Windows were a tenth as innovative as the XBox division or even Zune, MS could probably swing a turnaround like Palm is in the middle of.
In fact, I'm calling it now: Allard's going to be CEO of MSFT before 2020. Maybe before 2015. You heard it here first.