It would be a mistake to discount the Romney candidacy at this point. He's polling well in Iowa (where McCain and Guliani have dropped out of the 'straw poll'), and is moving up in New Hampshire (close to home, as the recent governor of Mass.). If he were to win both of those when the actual voting takes place, or perhaps even wins in just Iowa and comes close in New Hampshire, he could move into this shortened primary process in very good shape.
But then the general election comes, and Romney would have real problems (against Obama, but much less so against Clinton) because of his shifting positions on issues key to the Republican base. Will they stay home if he's the nominee? Not if Clinton is the Democratic nominee- they'll turn out in big numbers to vote against her. But what if Obama gets the nod? Then we'll start hearing sound bites and seeing video tape of Romney's contradictory stances, and see more cartoons like this one.