So it's a little early to speculate but it would be interesting to see what different people are thinking about the front runners so far. Here's my drive-by analysis, subject to change of course:
Mitt Romney is the man. The media is tarring him with Mormonism and all the baggage that entails but he's handling it deftly so far. He's a good speaker, a self made gazzilionaire, and a problem solver. This guy has the stature and the bearing that a president should have (which our current president sorely lacks!). He's socially conservative enough to carry the South but slick enough to carry liberal states (he was after all the governor of Massachusetts). So far he's not polling so high but all that will change.
Hillary Clinton is too polarizing. The media loves her but she carries a lot of political baggage from her husband's years in office. If she is the Dem nominee every red state from the last election is going to be a red state this election (and probably a few new ones). She's obviously very driven and ambitious but she just doesn't have the character to be president.
Obama is too inexperienced and he's black (let's face it, this is poltically a detriment in some parts of America). The media has been pathetically drooling over the guy but the honeymoon is starting to end now that he's challenging Hillary. He needs to build more credibility. Just what does he stand for? We really don't know. He'll have a better shot after gaining more political experience.
John Edwards would probably be the best chance for the Democrats. He could probably carry some of the southern states. He has more credibility that Obama but lacks Hillary Clinton's baggage.
Giuliani has the 9/11 hero credibility but he's too liberal to win the Republican primary, case closed.
John McCain is too old. He just doesn't have the stature to be president. Let's face it, the guy is destined to always be the supporting actor and not the star.
I have a feeling that Al Gore might make a "surprise" entry into the race right before the primaries. He was after all a micron away from winning in 2000, and he's been getting great press lately.
My personal favorite, Ron Paul. He actually assesses the constitutionality of bills before voting on them, and he consistently votes against pork spending for his own district. He votes to keep taxes low and spending down and wants to keep America out of most wars. Therefore, he doesn't stand a chance