Perspective of a Canuck who's been watching too much US-TV on winter break:
So, what's been going on with Guiliani?
He finished way behind Paul in Iowa and will likely do so in "Live Free or Die" NH (and Paul's candidacy has been exclusively a show-of-force for libertarians, independents and internet loonies for some time). And despite the "focusing on later primaries" story, Rudy seems to have been off of the radar of the networks and the public eye lately.
Huckabee put on a nice show, but considering he's been exclusively playing the Jesus-card, it's unlikely he'll pull out such a lead in states where evangelicals aren't the core of the local G.O.P.. As Brug said, he's liberal enough on some "social issues" to open himself up to some serious attacks from Romney and co. The religious-right block just isn't what it used to be, and can't be expected to carry someone so lack-luster on many other fronts (although the whole abolishing-the-IRS-and-reforming-taxes thing, which isn't too bad, seems to be lifted straight from the more extreme parts of Paul's agenda).
Beyond that, the GOP candidates all seem to be pretty much the same. Who's more eager to double Gitmo?
Obama seems to have recovered from the past couple of months of dwindling momentum and dreary performances. Kudos for not minding the traditional advice on race and electibility, and running a campaign that actually brought people out. At times a bit too messianic for my tastes, but you can't deny the momentum. Fairly reasonable, slightly left-of-center policy proposals also help.
Edwards is to the union/working-class-activist crowd what Huckabee is to the religious right. Probably a viable future candidate for a possible socialist off-shoot party of the Democrats, if the U.S. were to go the route of West-Europe/Canada party systems.
I don't feel I can say anything about Clinton that hasn't already been run through the wrung of news talk shows - except perhaps that she's no Bill in terms of charisma. Certainly a polarizing candidate, especially as the retarded 25% of the U.S. populace still believes her husband was some grand evil of cartoonish-proportions.
If a voting U.S. citizen, I'd go for Obama if he was against Romney/Huckabee/Guiliani, and libertarian/independent otherwise (I'd rather see a viable third party come in than go Paul's way and try to resuscitate the dwindling Republican libertarian block).
My $0.02 (which is $0.0199710 USD at the moment. How about that economy?)