I think Palin is an opportunist. If Obama doesn't fall flat on his face I don't think she runs in 2012 but rather will hope Obama wins a 2nd term so she can run in 2016 when we'll have fresh candidates on both sides. Winning a seat in the senate makes this a lot easier because she can remain in politics and the public eye for 8 years.
Being a senator isn't that big a deal. Plenty of morons, kooks, demagogues, dimwits and doormats have filled the position. Dole was a classic, non-effective doormat. Palin would fit another category.
McCain pretty much sought revenge against Bush for beating him in 2000. He came out against Bush tax cuts, veered strongly leftward to oppose much of Bush policy in the Senate, to the point where (depending on the source) he approached the Democrat minority, offering to switch to independent and caucus with the Dems to give them the majority (or, he was approached, and seemed receptive to the idea). He reportedly sought to defeat Bush in 2004, but 9/11 changed his plans. If you look at McCain's voting record, he was one of the Republicans most opposed to Bush leading up to 2004, then, preparing for this race, switched to make the "90%" claims true leading up to this election. I don't therefore know what McCain's core principles are. Obama didn't pull Bush/Rove's South Carolina adopted-Bangladeshi-as-black-lovechild, but I still think McCain views Obama with contempt. McCain has nothing left to lose, his reputation badly tarnished by this campaign. He may run for reelection in the senate, but his viability as a presidential candidate is done. I'll take the opposing view and predict he acts as a public thorn in Obama's side, leading the calls for filibusters as the only stopgap against Obama/Dem policies. A Republican Ted Kennedy.
There is no way Palin disapears. She craves the media IMO and really won't care whether it's in politics or media. She will find a way to get her face on TV. McCain I hope is done after he finishes this term. Heck if the GOP could have come up with a candidate that didn't look dead and that conservatives could rally behind things might have been different. I couldn't find one conservative that was excited about McCain they just didn't want Obama. It's extremely hard to overcome the hate that Bush created with a candidate that nobody really likes. Especially when the opposition is an excellent speaker who is very charismatic. Obama has an opportunity to do more good for this country than any president in history, they all have, but Obama has a congress that should be on his side. One thing is certain, if he is a do nothing president he really missed the boat.
It doesn't benefit a maverick though. The Republican base has become overly liberal while still trying to maintain lower taxes. McCain is really an independent who has Republican next to his name.
I know people were talking about the chilled body language between palin and mccain, but this is a good example. Like Randy Pausch said in "the last lecture", you can always tell if the presentation is going to be good by the cohesiveness of the group. If they're standing tightly together and making eye contact, its good. If they're standing apart and avoiding contact, its bad. It was bad.