Ballmer Says Elop A Candidate For Microsoft CEO

Can someone explain to me why Microsoft would consider this guy for CEO? Was it his two years heading up Microsoft's Office division? Was it his performance at the helm of Nokia?
In a comment that should surprise no one, Microsoft Chief Executive Steve Ballmer said Tuesday that Nokia's Stephen Elop is a candidate to replace him. "Stephen will go from external [candidate] to internal," Ballmer told the Seattle Times, though he also said the Microsoft board will evaluate all candidates.