I doubt Palin gets the nod. From my understanding, there are many in the Republican base who now want nothing to do with her, as they believe walking from the Alaskan job was not seen in a good light. And were she to get the nod, I think she would be absolutely destroyed in the general election. But, she could also get thrown to the wolves should the GOP see the writing on the wall.
Romney? I doubt it. He lost many votes simply because of his denomination.
Oh, and that also means Jindal will also get the boot. Those who are unhappy with the election of Obama because of his color (and, yes, they are out there) would absolutely implode should Jindal get the GOP nod. That, however, might be good news for a third party to make their move.
Crist? Perhaps - but he doesn't quite have the name recognition. Perhaps he can build up a reputation, but he needs to do it quickly (remember, Obama had mega-points, thanks to his DNC speech).
Jeb? There were quite a few who would have rather had him and W. He was seen as more responsible, level headed and capable over his over-grown frat-boy brother. Unfortunately, I think that frat-boy has pretty much dug him into a very deep hole. Yeah, he might be able to dig himself out of it, but I think he has too much work to do.
Huck might have a chance amongst the GOP, but I think he might be a bit too far right for the rest of the nation.
For the Republicans' sake, this "other" guy had better really start working for votes.