When Steve Ballmer said he was retiring, he said he would leave in 12 months.

People at the company we spoke to said it would likely happen much sooner than that.

Bloomberg News is confirming what employees thought, saying the board wants to have a new CEO picked by the end of this year.

So, far Bloomberg reports that the board has talked to four people: two outsiders, and two insiders.

Here's a run down of each of the candidates.

Alan Mulally AP Outsider #1: Alan Mulally, CEO of Ford

PROS: Mulally is friendly with Ballmer, and consulted on Microsoft's recent reorganization of the company. As a result, he has some idea about what's happening at Microsoft, and what needs to happen at Microsoft to get the company pointed in the right direction.

He was a dynamo at Boeing, which is where he was before Ford. At Ford, he didn't need government bailout money, and has successfully led a transformation of the company.

CONS: He's old — 68 years old. Does he really have the energy/desire to run a massive company like Microsoft? He doesn't have any high-tech experience. He's also not seen as a visionary. Can this guy fend off aggressive companies like Apple and Google? Does he have a clue about what's coming next in personal technology?

Pivotal CEO Paul Maritz EMC Outsider #2: Paul Martiz, CEO of cloud company Pivotal

PROS: He was CEO at VMWare, and did an amazing job. He has a lot of experience with enterprise businesses and understands cloud computing. Microsoft's future is in enterprise products, so he's perfect for taking the company to the next level. He previously worked at Microsoft, leading development of Windows 95, which was Microsoft's pinnacle.

CONS: He was close to retiring, and it's unclear if he has the passion to take on a job of this magnitude. He doesn't have experience in leading a turnaround, which is what Microsoft needs.

Steve Ballmer and Stephen Elop AP Insider #1: Stephen Elop, CEO of Nokia

PROS: Technically he's an outsider since Nokia is still an independent company. But, Elop is an insider. He led Microsoft's Office division for three years before he went to Nokia. He knows Microsoft, he's been the CEO of a public company at Nokia, and he has a technology background.

CONS: The reason he's coming back to Microsoft is that he failed to save Nokia. The company lost a lot of value under his leadership. He showed no particular vision or insight to smartphone market. What would he bring to Microsoft that would significantly enhance operations?

Tony Bates Matt Rosoff | Business Insider Insider #2: Tony Bates, ex-CEO of Skype

PROS: Bates has a good mix of enterprise and consumer experience. He worked at Cisco before taking over Skype. He's spent enough time at Microsoft to take its temperature, but not so long that he's indoctrinated into the old way of doing things at Microsoft. His staff seems to like him at Skype. His current role is as a guy hunting for new opportunities for Microsoft.

CONS: He ran Skype for less than a year. He's never run a public company. Does he have the managerial skill to run an organization as gigantic as Microsoft?