I'm going to answer my own question from yesterday, based on last night's results. The Republican nomination contest is essentially decided.
Bold words after just two states? Consider the results of the candidates placement from last night:
Romney- Got more votes than he did in 2008, got a higher percentage than McCain won by in that same year, and was not far away from 20% ahead of the next comer. If anybody got positive momentum for South Carolina last night, it was him. Yes, SC is not a good state for him, and Perry and Gingrich are both sitting on millions in advertising they can unleash against him over the next ten days. But you'll see below why I think it won't matter.
Paul- Strong second last night, following up on a strong third in Iowa. South Carolina will be a little harder for him, but he's probably in a position to keep getting double digit seconds and thirds in many states to come, if he chooses to stay in. But is unlikely to ever do better than that.
Huntsman- I actually like him a lot, but then as a Progressive I would, for the same reasons in reverse that Joe Lieberman used to be the Conservative's favorite Democrat. It doesn't matter, because New Hampshire is probably the only state until maybe Utah that he can score double-digits in, and it's only a matter of time until money and/or a sense of futility forces him out.
Gingrich- Squeaking ahead of Santroum isn't a bad result for him, but being fourth isn't a good one either. What this not-bad-enough-to-knock-either-one-out result really means is that they'll both be in through South Carolina, along with Perry. Which means that Romeny, who would probably lose the state by 10-15% against a united Conservative candidate, will win it.
Santorum- Fifth ain't great, and his Iowa momentum is now officially tapped out. Nearly tied with Gingrich, though, means he'll be alive and kicking in South Carolina. It's possible one of them will decisively pull ahead of the other there, leading one to drop out. More likely, they split the conservative vote pretty evenly, and are both encouraged enough to stay in through Florida at the end of the month, dividing the vote there and delivering that state to Romney as well.
Perry- Skipped New Hampshire to make his last stand in South Carolina. The problem with doing that, of course, is that people write you off after two single-digit performances in a row. Presumably he'll give up the ghost after three in a row.
The upshot of all of the above? By the end of this month, Romney will have won the first four contests. The field will effectively be winnowed down to him, Paul and whoever the last Conservative standing is. Yes, technically it will take him a while to officially pile up the delegates needed. And some opponent will probably score a surprise victory or scarily-close second here and there. But the early division of the field will have gotten him enough ahead that nobody will be in a position to catch him. Finis.