I agree with Michael Tomasky that Newt Gingrich is never going to be the Republican nominee, at least at the top of the ticket. I actually think the position Gingrich has been running for all along is that of Running Mate. If the nominee is Romney, he's going to need to do what McCain did: Pick someone that the extreme right-wing of his party will love…but hopefully a better campaigner than Sarah Palin. (Actually, Palin turned out to be a pretty good campaigner for the career advancement of Sarah Palin…just not so good for McCain/Palin.)
But I disagree with Tomasky that the Anyone-But-Romney crowd is going to be a problem for Romney, if and when he gets the nomination. Right now, there's still time. Those folks have the luxury of trashing Mitt in the hope that they can cause someone more to their liking to be the nominee. It's like in the last election when McCain looked close to having the nomination sewn up. You had people like Rush Limbaugh and Ann Coulter saying they couldn't support him; that he'd be worse than Obama and that they might sit this one out or even hold their noses and vote for a (gasp) black Democrat.
And then of course when McCain became the guy, they supported him. Enthusiastically.
My prediction, for what little it may be worth, is that if Romney does get the nomination and picks a better Palin (who I doubt would be Newt), all the folks who now oppose him will decide the following: That what they hate about Romney isn't nearly as much as what they hate about Obama. And they'll support their party's nominee as fervently as if they really wanted him.