I doubt seriously that if Romney runs for re-election as governor, he will then turn around and run for president. He will do one or the other or neither, but not both. If he announces for re-election, he will be virtually forced to pledge that he’ll serve out his term. Also, for what’s worth, I don’t think he’s a sure thing for re-election. See this. He’d probably be the favorite, but it wouldn’t be a cakewalk.