I actually made it to the theater for this movie!
I really wanted to see this movie after the spectacular viral marketing campaign and knowing that JJ Abrams was involved. (I love Lost, Alias, and MI:III) Therefore, I was really disappointed by the movie. It seems like a universal rule: The greater the hype, the bigger the disappointment.
Aside from being shot in genuine shit-o-vision (the movie takes a Blair Witch approach, but turns of modern video camera features like screen steadying to make the picture jerk around barf-tasticly), the film just doesn't ever get over the main characters being fucking goofy morons. The main camera operator is a dumbass until the end, making stupid remarks like a hero from an action movie. That's pretty standard, except this movie is supposed to have been shot by real people! I silently cheered as each of the wooden actors was killed off. Good riddance! And good luck with that acting career.
As far as story, you never learn anything about the monster or what the fuck is going on. You're expected to hunt down tidbits of information on the web. Yeah, I don't know about you, but a movie is a movie. When it's done, I don't want to spend five hours trying to figure out what the fuck was going on in the movie. I want to have been entertained, maybe challenged a bit, and then move on with my life.
So as far as Cloverfield, you might want to take a pass and wait for the next field. I hear they have poppies there.