There is no freaking out but nothing that happened today made the likelihood of Trump or Cruz steamrolling the GOP nomination any more likely. If anything, it makes Rubio (the establishment dream) a very plausible GOP nominee. Sure there is the idea that Trump's camp can suck up Cruz's votes and vice versa just as the establishment can rally and consolidate on Rubio vs. Cruz or Trump. In such a scenario, I'll lean GOP establishment.
Hillary will likely be the nominee but nothing is ever on stone. Bernie is an absolute bust vs. Rubio, that I can guarantee.
The Iowa caucus doesn't matter that much.
The establishment was always going to coalesce around Rubio, he has the same problem he always had -
He's a shit campaigner and he staked a couple of positions which are problematic with the large part of the Republican primary voters.
This was true before tonight and true after tonight.
p.s.
While I definitely think that Clinton is more likely to win against Rubio than Sanders (I generally think that barring Wall Street blowing up the economy this fall, a huge terror attack or getting caught having sex with a black man, Clinton is the next president) I have no idea why you think that Rubio crushing Sanders is a forgone conclusion.
It's very hard to predict things so far out, but he's consistently beating him in head to head poll.
Yeah, it's hard to imagine America electing something with anything that even rhyme with socialism in their platform, but could you have imagine the US voting for a black guy?