Israel?
If there is an increase in terrorism because of an Iraq war it will be "easy" targets that hurt America and allies.
Plus, how much news is a terrorist bomb in Israel going to create, compared to one in London, Madrid or Rome (sorry, callous but true)?
Domestically, I don't see the logic behind thinking that the big events (Superbowl, July 4th etc) are the most likely.
Security is (supposedly) tighter around these events. Not as easy a target.
Was anything special about 9/11? Nope, but it's now a day that will be remembered for a long time.
Cheers,
Tony