The debate was very solid for Paul, and while it may not be enough place him in the top two in FL he hasn't been focused there so a low finish in FL doesn't really hurt him.
The media could in theory try to focus on SC + FL as a "trend" but that's pretty much worst case and isn't that big a neg impact compared with just being ignored as as been the overwhelming norm. Paul is focusing on Maine, Nevada & Minnesota those are the places he really needs to do well. A win in one of them, being able to say Ron Paul takes 1st place in ____ shortly after FL will be important, the lack of that could really be a blow.
Honestly my fingers are crossed for a Newt over Mitt finish in FL, it may not happen I acknowledge but it would be a boon to the Paul campaign if it did (SC helped a great deal, FL would extend those effects further still).
One other positive about this debate is the continued trend of Santorum and Gingrich to court Paul stances/voters. Most Paul supporters are not going to be swayed by that but it erodes the "fringe candidate" narrative and makes more of the Newt/Rick voters likely to vote Paul when their guy drops (and in those states where their guy isn't on the ballot). The other aspect to keep in mind is that the further the delegates are spread the more the late states matter and the more likely a brokered convention becomes (which could really turn in Pauls favor if the ground game is as good as Iowa ect. seem to indicate. )
Finally FL is to some extent a win for Paul even if he finishes in fourth with Mitt taking the head of the pack. The comparative resource investment is advantageous to Paul. FL is expensive and Mitt has already spent over 10 mill there so far (including spending by PACs) that's money which will not be spent in other states and other contests thus helping Pauls long game. Remember this year FL is only worth 50 delegates and with the way the media has treated Paul all cycle is bid for the nomination doesn't live and die by the Pendents / reporters the as much as the other candidates.
All in all, good debate and nice direction for Dr. Pauls presentation of himself and beyond that don't sweat Florida one way or the other.