I sure hope so but it happened once a little over 5 years ago and I don't see any significant change except that now it's harder for your average American citizen to travel by plane. If something like this happens again, I wouldn't want to look muslim in this country. While there may no be any government action without huge public outcry, and I expect it would be minimal at best, just enough to quiet the masses, I think the average citizen will be much more willing to take action himself.
Interesting choice of words
Did you ever notice that whenever any kind of calamity happens, the first thing on the news is an assurance that it absolutely isn't terrorist related. This always comes even before the full extend of whatever the event is is known...so if and when the real attack comes, we will be assured it was just an accident.