It's hard to suggest sensible names, even from a distance. Microsoft is such a diverse company in terms of Enterprise and Consumer focus that there are very few candidates who would make sense.

I'm not very familiar with the MS internal candidates. I'd note that it would be pretty unlikely that the board would appoint an internal candidate who wasn't on the "Senior Leadership Team"[1]. That would mean none of the "Scotts" are candidates, but Satya Nadella[2] is. Nadella has done a pretty good job the MS's enterprise cloud strategy: Azure is a decent platform. However he has no consumer background...

Exceptions to the "must be on the Senior Leadership Team" might be made for people from semi-autonomous divisions. Stephen Elop is one such candidate (who has consumer experience) and Tony Bates is another. Bates has a very well rounded resume: self taught programmer, ex-CISCO (so knows enterprise), ex-Youtube board (so knows media), ex-Skype (so knows consumer).

Outside the company.. hmm. Vic Gundotra or Sundar Pichai from Google? I looked through the Oracle & IBM leadership teams and no one jumped out at me (except for Mark Hurd, but I don't think that will happen..)

The person they really need is a cross between Andy Groves[3], Phil Knight[4] and Jack Welch[5]. We've had a Groves/Welch cross[6] and a Groves/Knight cross[7], but getting all three at once looks hard.

[1] http://www.microsoft.com/en-us/news/exec/slt.aspx

[2] http://www.microsoft.com/en-us/news/exec/nadella/default.asp...

[3] http://en.wikipedia.org/wiki/Andrew_Grove

[4] http://en.wikipedia.org/wiki/Phil_Knight

[5] http://en.wikipedia.org/wiki/Jack_Welch

[6] http://en.wikipedia.org/wiki/Louis_V._Gerstner,_Jr.

[7] http://en.wikipedia.org/wiki/Steve_Jobs