AP
One of the front runners is Ford CEO Alan Mulally, known for overhauling Ford's culture.
Turns out, Mulally has already tried to do the same for Microsoft.
He was the mastermind behind Ballmer's reorg last summer.
Ballmer hoped the reorg would change Microsoft's culture of fiefdoms, where employees and business units were pitted against each other, into one big happy family that worked together. Ballmer even named the reorg "One Microsoft."
Mulally helped Ballmer plan it in a Seattle-area Starbucks on Christmas Eve, according to an interview with Ballmer by the Wall Street Journal's Monica Langley:
Mr. Ballmer brought a messenger bag, pulling out onto a table an array of phones and tablets from Microsoft and competitors. He asked Mr. Mulally how he turned around Ford. For four hours, he says, Mr. Mulally detailed how teamwork and simplifying the Ford brand helped him reposition it.
A lot of people are rooting for Mulally to become the next Microsoft CEO. Some people thought Ballmer was emulating Mulally with his reorg plans but looks like Mulally was in on the plans from the beginning.