I don't think (or at least I hope) that passengers will allow hijackers to take control of the airplane after this. I think many people thought of hijackings as events with happy endings before the attacks on Tuesday.
100+ people could easily overpower 5 guys armed with box cutters. They could tear them apart, in fact. Looking at the lists of the dead on each plane, and seeing the names of young, possibly able-bodied men and women, I'm surprised that only one small group on one plane seems to have resisted the terrorists.
I mean, if someone pulled out a weapon on a plane that I was on, I'd attack him. (I felt that way before this, too) Am I alone here?
But, security... I'd have to go with the 'naked' plan (with enema). Someone could always sneak a non-metal firearm on board in one hole or another...