I can't guess when, but sometime before the next presidential elections I expect a second 9/11 type incident.
Unfortunately, to be effective, the ante would have to be raised. The goal will be to empower the current regime with extraordinary powers. The only way Congress will concede to such a thing is if an incident of extreme magnitude takes place and the threat of further such incidents remains in the offing. As part of the granted powers, the presidential elections of 2008 would likely be canceled as an emergency measure.
I don't think toppling the Sears Tower will do the trick.
A nuclear event is the most likely scenario that would carry sufficient persuasive weight with the American public and Congress.
Should this occur, members of the 9/11 Truth Movement can only expect to survive if they move underground and it's doubtful that they would ever again be a serious force to be reckoned it, given the expectation of a declaration of martial law throughout the U.S.
The fact is, if 9/11 was an inside job, the perpetrators have committed themselves too far to let it all fail, unless they believe the next government will be somehow compelled to continue policies that the current one initiated (Iraq, Homeland security measures etc.).
It's quite possible that 9/11 Stage 2 is already in place and timed to be initiated if and when it's absolutely deemed necessary. The reason we haven't seen it so far is because it will be so horrific that they don't really want to "push the button" unless they feel it's absolutely necessary to maintain their initial goals.
I know looking at these words, it all seems so outlandish, like some cheap thriller vacation reading, but when you think back to 9/11 and events like WTC 7, if you really believe it was an inside job, after deliberately killing 3,000+ innocent people, how likely is it that those responsible would chicken out now?