I liked the moive (I just saw it yesterday at the theater it's premier weekend for it over here).
I liked not knowing anything about the monster itself; what it was, where it came from and what happened to it.
The camera hand shake was a tad overdone and could have been toned down a bit.
BUT
What I like the most about the film is that I'm still thinking of these things this long after seeing the film. I don't think I have done this with any movie in many many years.
This lead me to see what more theories circulate on the net and I started to discover all kinds of fun stuff that is associated with the "viral" marketing campaign.
All the characters in the movie has a MySpace page and they are all friends with each other. (Huds MySpace page as an example
http://www.myspace.com/hudsonplatt)
Several video clips about events surrounding what happened:
Here's another example
http://www.youtube.com/v/KarNwKx5mGY
A homepage for a fake company involved in some events in the movie
http://www.tagruato.jp/
The page for the company Rob is going to be Vice President for
http://slusho.jp/
I guess I fell for the hype, but only after I saw the movie itself. Now I want a sequel that explains everything >.<