I believe Mitt Romney will win the Republican Nomination, after taking out Iowa, New Hampshire and Nevada. He will be unstoppable, if Romney manages to pull off this feet. For Vice President, Governor Romney would select the conservative Senator from Kansas, Sam Brownback.
Whilst on the Democratic side, I believe it will be a two man fight for the nomination between Hillary and Obama, with most of the other candidates dropping out early. After months of battling for the nomination, Hillary Clinton will emerge the Democrats nominee. For Vice President, Senator Clinton would select the experienced Governor of New Mexico Bill Richardson.
The election would probably be close until the final weeks of the campaign, where the Democratic ticket of Clinton/Richardson would emerge victorious over Romney/Brownback.
Clinton/Richardson 321 EV 51%
Romney/Brownback 217 EV 47%
Third Parties 0 EV 2%