Outside of the immigration question, Next won the debate. That being said, his answer will hurt him, the question is figuring out how much. My guess is much less than Perry (and possibly much less) because, oddly enough, Perry had more Republican support at that point, and combined it with an utterly amazing ability to not communicate at the same time (a double-whammy of sorts). I might as well mention that, on all the issues out there, jmfcst is least reliable as a Republican bellwether on this issue being that he's from Texas. The Republican base in Texas is in a different world on this one than most other Republican bases (see, e.g., Iowa)
Let me also add the various attempts Romney makes at pandering are beyond bad, and are starting to make me really think that the anti-Romneys might even take a gander at Ron Paul if Newt flames out. Seriously. I have never seen anyone as unbelievable as Romney is on this, and I've seen quite a lot. No wonder he's stuck with the same numbers as always.
As for the others, Cain is once again completely outmatched by normal questioning. Perry did ok, but tired out before the end (as always). Ron Paul was Ron Paul. Bachmann is very good at attacking others in her own way, but brings nothing new to the table. Huntsman is, of course, an asshole, but performed better in this debate than before. Santorum, well, who cares...
I think you would be surprised to hear that a decent number on the most conservative sites are coming out in agreement with Newt's answer because it puts such a far out "statute of limitations" that it can't be construed as a magnet. Nobody will come because people who've been here for 20 years are staying and people who've been here for a few years are getting the boot.
So there is some disagreement. But ultimately its still pretty quiet. Conservatives are currently in the middle of a respectful and thought out debate on the topic right now!