The most likely effect will be the loss of some international carriers who are losing money anyway, but will be harmed by a down turn in the economy which is coming now.

AA and UA may collapse or shrink if the UA threads are to be believed.

I think what we know is nothing! Everything is specualtion but I expect an initial clampdown - for example the ban on in-bound non US carriers flights - in the short term.

I suspect that for all of us things will never be the same again on a number of levels.