I was not impressed with this movie. Having expected a more-or-less real time exploration of the couple of hours in which the shit went down, I was disappointed by this very formulaic rescue story about two guys. Despite the fact that this apparently actually happened (I'm talking about the rescue thing here, not the actual attack - I already knew that happened.) and is therefore by some estimations allowed to be formulaic, there are thousands of other stories that could have been told about that day that a) were more central to the main events and b) weren't identical to hundreds of rescue movies already made. Even for those who say the story should still have been told, fine, but to say that it's a movie about the world trade center is a bit misleading, which the title subtly implies.
On a different note, is it strange to anyone else that the same guy who plays Jake Gyllenhaal's father in Brokeback Mountain also plays Maggie Gyllenhaal's father in World Trade Center? I can't say I see a resemblance.