It seems like too good a chance for them (or some other assholes) to pass up, especially considering their testosterone poisioned mind set.
The threat to kill a million children (although these guys are too stupid to count that high) brings to mind Disneyland, Six Flags or the like.
If any are caught, will the Government announce it, or will they want to keep the bad guys in the dark about what happened to their guys and how they were found out?
You just freaked me out. 
I’m gonna be in Disney World on the 4th. Well, not all day, but late afternoon and night, which is when I presume omething will happen if it’s going to. I just heard on the news that Sasam Hussein’s step-son was arrested in Miami and had plans to attend the flight school where the 9-11 hijackers attended. So if he was going to have something to do with an attack it would not be on the 4th, since the lessons hadn’t started yet, but who knows? Oh well, I won’t do anything different, but I’ll just be cautious.
A certain episode of MAS*H comes to mind. Hawkeye made a bet and swore up and down that B.J. wouldn’t “get him” with a practical joke. All day Hawkeye became more and more paranoid as he tried to head off any potential B.J. gags, until ultimately Hawkeye ended up sleeping on a cot, surrounded by barbed wire, while holding a golf club–all just to be sure that B.J. wouldn’t “get” him. And that’s when he realized that B.J. had pulled the ultimate “gotcha”–by making the victim get himself.
Granted, scumbag murderers will take every opportunity to gain a political advantage. If Al Qaeda has some grand plan together for the 4th and they’re really determined, they’ll try something. But keep in mind also that part of the terrorist’s game is just a darker version of Hawkeye and B.J.'s bet–they want to get us by making us get ourselves. (i.e. by acting so paranoid that we trust no one, by acting afraid all the time)
The only thing AL-Queda will be doing on the fourth is getting shot up, bombed, flame-thrower bar-b-qued, or skewered with a K-bar. They won’t appreciate it, but we do. Happy Independence Day!
Any terrorist with half a brain would know that security would be very high around July 4th (jet fighters patroling the sky fgs!) and would not try anything then. Unless… it was a really fanatical terrorist who a) wants to be ‘dramatic’ by doing something on a famous day and b) wants to prove that he can do something amid high security.