Newt Gingrich, which a lot of people had thought dead (and I thought could have won Iowa: http://conservativelyliberal.blogspot.com/2011/12/iowa-caucus.html), has made a major comeback.
I think he is likely to be the GOP Nominee. This is not just because South Carolina has historically picked the nominee. Frankly, Romney has repeatedly failed to turn his solid, dependable 25% following into anything above 35%. Too many people are suspicious of Mitt, and Gingrich has gathered the support of most of the wings of the GOP. He is moderate enough to attract the moderates, talks the religious talk (if not faithful to it), has enough T-Party support (even though they would prefer some of the off beat women - Palin/Bachmann.), and has enough of the old time reputation to get the wealthy. More importantly, he has a rep of being a tough fighter.
All of which makes for a good thing for Democrats. Romney is more of a moderate and does better against Obama. The most recent polls has Obama beating Gingrich by 11% (51 to 41). This compares with a virtual tie for Romney vs Obama (47 to 45) (Source)
Yes Santorum won a single state. But only barely, and it is a rather conservative one. The rest of the country isn't going to support his brand of religious insanity.
Honestly, as we have already pretty much got rid of the crazier folk, it won't turn out too bad. Santorum, Bachmann, Cain, etc. were more about radicalizing the government, than Romney or Gingrich. They wanted to make major changes. Mitt and Newt on the other hand are for small evolutionary changes, even though they talk a big revolution.
As a final note, I believe Newt is the likely GOP nominee. The T-Party has enough power and is zealous enough to reject anyone moderate. Romney is more moderate than Newt, so I expect their support to push Newt Gingrich into a failed presidential bid against Obama. The T Party cares more about pushing their own radical agenda then about winning the election - and are not political savvy enough to understand just how many people dislike their agenda.