Whole lotta kneejerk crappy political analysis goin on up in here.
First, the "nobody has ever won the nomination without winning Iowa or NH" conventional wisdom means almost nothing in the dynamics of this particular race. This is because the "pragmatic conservative vote" (or "establishment vote") is still badly fractured. Trump and Cruz have already won their "lanes" (outsider and fiery conservative, respectively), but the pragmatic lane is still jammed up. It will not remain so for long.
We're now down to a 4.5 man race. Christie will likely officially suspend his campaign soon, and Carson may or may not, but he's effectively done. Trump, Cruz, and Rubio already punched their tickets in Iowa, and NH has not changed that for Rubio. Last night wasn't a good showing for Rubio, but it wasn't terrible, either.
Kasich punched his ticket in NH. Bush finished in 4th narrowly behind Cruz - in New Hampshire. That's bad, but he'll limp along for a while longer. That's your 4.5.
I still think this was the high water mark for Kasich and Bush, and they'll fold by Super Tuesday, giving extra bounce to Rubio, and then we'll be down to a 3 man race.
Ultimately, this hurts Trump the most, as I just can't see him crossing that 33-35% threshold.
It is really telling how much the media (and certain posters here) are salivating over the prospect of Rubio losing - they are worried about him.