I think Palin will run. She's ambitious and doesn't let reality stop her. I don't see her winning, though.
If Huckabee runs again (not sure if he will; didn't it seem sometimes like he was having a lark rather than really competing?) she won't be the #1 choice of evangelicals. Romney will do well among the managers and Chamber of Commerce types who make up a big chunk of the GOP donor base.
Another thing: some Republican primaries are winner take all and some are proportional. In '76 that made their nomination fight longer and closer when Reagan won Texas. This time it cut it short in McCain's favor even though he and Romney should have been about tied.
The WTA states (NY, NJ, FL, MO, and CA) would tend to favor a more moderate candidate, I'd think. This time it's McCain. Who knows who it would be in four years.
Oh, and I don't see anyone getting anything close to Bush's 2000 monopoly on the party's institutional support. Maybe Romney, but I seriously doubt it.