Hillary is an obvious pick. She's been First Lady, Senator and Secretary of State. There's a clamor for her to run and I just don't see anyone on the horizon who could take frontrunner status away from her. My guess is that by 2016, her vote for the Iraq War Resolution will be a distant memory. Assuming she's the nominee, expect every scandal the Republicans tried to pin on Bill and a few new ones to be thrown at her.
Why Christie? Because of two things. Firstly, he's trying to lose weight. That will appeal to both those who are overweight and to the people who tune into the weight-loss reality shows. Don't kid yourself, a lot of people really are that superficial. They'll vote for a good story instead of a good president. Secondly, he has a type of bluntness that Republicans confuse with plain-speaking charm. I think he's a bullying prick but Republicans like to run mean guys. He's also very conservative but not a Teabagging whacko.
I could be wrong, of course, but my gut tells me it'll be those two.