I think that Olympia Snowe could take a crack at it and be mildly successful in New England. I don't think she'd make it past the primaries because she is pro-choice and voted for Stimulus Senior.
Perry will be decimated. He's Texan and has a southern drawl. Too Bushian. There are only two possible southerners that could run and they are Mike Huckabee and Bob McDonnell. Rubio will be to green to make a run, his chance is 2016 or later should we not win and we will run Rubio in the future.
There are five key qualities we need in a candidate:
1)Money Machines - No one has this except Palin and Romney
2)Not Southern (except Huckabee or McDonnell) - many possibilites, I imagine we'll stray from the plains states as well - most of the candidates from the plains are boring
3)Excitement Factor - Only Palin has this right now
4)Solid Conservative - many choices, Romney's weakest here
5)Articulation of Views - Palin's weakness, but she could be playing it that way to catch people off guard.
You forget one:
6)Not a nutcase, crook, crank, or extremist.