Just some quick thoughts before work:
1) This is clearly a race between Romney and Perry. That was felt to be the case BEFORE the debate; but it was solidified last night.
2) Romney (IMO) came out looking and sounding like a Presidential Candidate; Perry as someone who solidified his position with the Tea Party and/or the Right Wing of the Party. What this means is that the GOP Primary is a toss up. With that said, Romney (IMO) would cause the most trouble for the President in a general election.
3) Romney and Perry finally "separated" themselves in two ways: a) as above and b) on Social Security. Perry feels that it, as a "Ponzi Scheme", should be completely eliminated in it's current form; Romney feels that it simply needs to be fixed. This will most definitely be a point-of-contention on the Primary trail.
4) Bachmann lost the momentum she had. In many ways (IMO) her and Perry were fighting for the same base, and Perry won. I think she is out.
5) Huntsman and Cain.
Huntsman really would be a great President, with his experience in State, National, and International affairs; and his grasp of economics, business and what needs to be done for our economy. But he is almost "too" calm and uninspiring (regrettably).
Cain has some great and bold ideas...that would never get passed. I also think that he is too easily rattled and would self-destruct, with time, with the brutality of the campaign trail.
6) Ron Paul
I'm as "free market" as the next guy; but I don't think that the "free market" is the answer to EVERYTHING any more that the government is. He also came off as rambling with many of his answers. He obviously is a man with a lot of interesting ideas and a passionate following. But he will never be President.
7) Newt's time has passed. He took a HUGE jab at the "Mainstream Liberal Media" accusing them of wanting the candidates to argue amongst each other. Otherwise, it was more about reciting his resume and all that he had been a part of (including the "Reagan Revolution") and the economic prosperity of the Clinton years.
The most interesting thing to me will be Romney and Perry campaigning a) in the "Bible Belt", and how much Romney's beliefs will come into play and b) how Perry will play in States like Florida with his stand on Social Security. (Older voters are the ones who come out and vote in Primaries, especially GOP primaries).
IMO, after last night, I think that The President would fair the best against Perry in a General election. Romney would certainly be the more formidable opponent against the President; but the question is will he ever make it past the GOP Primaries.