I thought this movie was great. I loved the "as is" presentation, there's no explanation given for anything that happens, there is no hero, not even any hit charting music soundtrack. The whole thing really does feel "real".
If there's a sequel, I'd really like it to be about the same attack but from the military perspective.
Here's a site that delves into the backstory that the movie glances over. MASSIVE SPOILERS INSIDE!!!
http://geeksofdoom.com/2008/01/22/cl...-and-millions/