For the Democratic primaries, Andrew Cuomo and Mark Warner are favorites in initial polling. Schweitzer manages to win Iowa comfortably, with Warner in second, but Warren wins NH, with Cuomo second. Schweitzer pulls out narrow wins in South Carolina (against Warner) and Florida (against Cuomo), before winning easily in Nevada. At some point Warren makes a Santorum-esque comeback and the race becomes Schweitzer vs. Warren, but Schweitzer was the frontrunner after FL and manages to get the nomination. Maybe Cuomo as Veep.
For the Republicans, Huntsman is a nonfactor. West may do well in early polling but ultimately is also a nonfactor, leaving Christie, Rubio, and Paul as the 'serious' candidates. Christie would probably try to lock up NH, leaving Iowa as being a race of Rubio vs. Paul. If Rubio wins, he probably uses the momentum to carry SC and FL and then becomes the frontrunner; if Paul wins, the race gets scrambled but ultimately Christie wins. Not sure about Veep, but it would have to be someone who has a 'nice' persona to balance Christie (I just thought of Angela Merkel before I remembered she's in Germany) -- Susana Martinez might be a good pick if she wants it.
Christie against Schweitzer would be a really fun race considering they both have a penchant for saying what they perceive to be the truth right to people's faces. It would be very different than the carefully-calculated Romney against Obama. After eight years of Obama (I'm assuming), Christie would probably win, but it would be close -- like this:
Christie/Martinez 288
Schweitzer/Cuomo 250
PA is the deciding state.