my own prediction, so someone can quote me and mock me for being wrong in a few months... 😉
unless a smoking gun comes out that directly ties Christie with this, I think he escapes with his national reputation in-tact, if a little dinged up. there's no chance this ends with him resigning.
I still don't think that he has a shot at the GOP nomination in 2016 if he runs at all, but signing the Dream Act this week was far more damaging to him in that regard than causing a traffic jam. the second he starts campaigning in Iowa, there will be ads blanketing the airwaves about Christie supporting illegals and wanting to give them all your jerbs and monies.
This sounds reasonable to me. The American people as a whole are busy trying to survive and aren't paying attention to politics. They know the corporations and the rich have taken any say they might once have had away.