Hillary Clinton: If she wants it, she'll take it. This isn't like 2008, when there was a huge section of the party that was against her. She's paid her dues.
Joe Biden: He's the only potential candidate that we know wants the job, because he hasn't been shy about making it clear. But he'd lose to Clinton, and I don't think he'd sweep the field if she didn't run. He's kind of let himself be pigeonholed into the comedy sidekick role, I'd like to see how he handles himself when running for office again.
Andrew Cuomo: If the first two don't run, he's considered the frontrunner. I'm kind of reminded of Giuliani though. New Yorkers with lots of name recognition, one big achievement that brought them scads of national attention, initial leads, and issues records too close to the center for the party to actually nominate them.
Martin O'Malley: His name comes up a lot and he seems like decent presidential material to me, but there's got to be a reason that he's getting such tepid support from his own party in Maryland after a string of liberal victories (death penalty, pot, gas taxes, gun control, offshore wind).
Deval Patrick: Like O'Malley, only with more scandals and less accomplishments. Pass.
Brian Schweitzer: Depends on how things go when he runs for Senate in 2014. On the one hand it's Montana, on the other he's crazy popular there. If he wins, he'd have pretty solid liberal credentials (gun control excepted) and still have won a very red state. Granted his style is pretty much the opposite of Obama, but if the hipster set wants another candidate they can vote for 'em.
John Hickenlooper: Worth talking about, and he's got some impressive policy successes under his belt. But it looks like he's going to have a serious fight against some not serious candidates in 2014. If he loses to Tom Tancredo, he's not going to go national.
Elizabeth Warren: Kind of the Ron Paul for internet liberals, only she's probably sane enough not to listen.
Antonio Villaraigosa: Almost certainly not going to happen, but he's the leading Hispanic candidate unless downtown jumps in.
I can't bloviate as much about Republicans because I pay less attention there and they're in a really chaotic space right now. But here goes nothing:
Bobby Jindal: We all know why he'd be good (big education, distinctive background) and why he wouldn't (Answering the SOTU speech is hard, but not that hard). What I'd add is that his approval ratings back in Louisiana polled at 38% back in April, way worse than they should be in such a red state. Obama actually runs stronger than him there.
Scott Walker: Not making a huge splash, but he's got chops. He pushed some really conservative bills past a light blue state, and survived the mother of all union backlashes.
Paul Ryan: Only House member elected to the White House was Lincoln. Paul Ryan isn't Lincoln.
Ted Cruz: I don't think the fact that's he's ridiculously conservative will hurt him, not given the base's hunger for Youtube-ready quips and the ability to prove that they aren't racist because they have a Mexican best friend. No, I think it's the fact that he's turned most of his Republican colleagues that will sink his chances in the end.
Rick Perry: I fell hard for the idea that Perry was the only plausible anti-Romney candidate, so I kind of want him to do well this go around and vindicate me. He's not the idiot that he came across as, and he might find a way to do it. With that said, I think Cruz is going to be sucking up all the oxygen in Texas.
Nicki Haley: Currently making noises about going to spend more time with her family after the one term. And as a mother with young children and a husband in the military, that's actually pretty plausible. Some people really do bow out of running for president to spare their families.
When it comes to the Republican nomination, I'm going to be watching high-profile endorsements like a hawk, specifically elected officials currently in office. They were a more reliable indicator than the news cycles in 2012, although that may have been unique to the facts of that election.