I believe CM Punk is going to win. It's a 70% chance they won't fuck up on that, because they know CM Punk will make them money in the future. If they play their cards right, CM Punk could have as much of a face turn as he could possibly get. Here's how:
<late match>
CM Punk gets laid out by John Cena, who does the five knuckle shuffle. However, CM Punk, not being completely beaten, reverses it and turns it into the Anaconda Vice. Cena breaks away, fight continures from there, and John Cena and CM Punk give as good of a fight as you'd see in a house show, only better for the cameras, and it ends with CM Punk giving Cena the GTS, or perhaps even an AA as if mocking the now-former champion and wins the match. He takes the mic, and says something to the effect of, "John Cena, I told you I don't hate you. But there was no way an entertainer was gonna beat a wrestler." CM Punk begins to walk out, and something happens, which no one expects.
Vince McMahon is at the end of the aisle, backed up by like six or seven lawyers, and explains that he managed to sign the contract before CM Punk tore it up. CM Punk protests, saying that it doesn't matter because he ripped it up. Then an educational moment shall pass, with Vince explaining quite plainly the fact that ripping up a contract doesn't nullify that contract, and CM Punk is now forced to work for the company, meaning that this is the perfect set up for CM Punk to turn from full-heel to anti-hero, a face that behaves quite like a heel but he's on the good side, setting up a fun Vince McMahon feud much like the Stone Cold vs McMahon battles of WWF. Granted, this is all dependent on whether or not CM Punk agrees to stay with the company, but this is a great way to manage "keeping the title in the company," explaining CM Punk staying in WWE, and keep the cash flowing in for more Punk.
Also, one of the better results would be Vince McMahon firing John Cena. Cena will need a break, as he's been overbooked and I've heard reports that he's been hurting for some time. This would be a perfect opportunity to give him that long-deserved break, maybe for two or three months. We get CM Punk, a great feud, and we get a break from John Cena for a while. Everybody wins!
We may even get ice cream on top of that.