I saw Cloverfield today at the theaters.
Expectations:
From the moment I finished watching the teaser for the first time my initial thought was: this is really well made. And from the style of the trailer it looked half-original and innovative; half-original being that Blair Witch Project already has used the same hand-held/up personal filming before. But then it took some time before the film actually went up in the theaters, so I guess my expectations of the film decreased over time - which actually is a good thing. Before watching the film, the only thing I've read and heard about the film was that the hand-held camera made people sick and dizzy.

My thoughts after seeing it:
I was blown away with this film. The strength of this film lies in its special effects and how they've put it together to mimic reality. The hand-held camera did give me a minor headache, but it was worth it considering all the unbelievable sequences that was delivered one after another. There are small things that might distract from the overall realistic feel of the film, such as the durability of the camera; which survives a dozen drops and even a helicopter crash. But in my opinion it's a fine balance between mimicing reality and a way to tell the story. To summarize, I would describe Cloverfield with two words: Rollercoaster ride.
I want to see it again, it was that good.
Edit: I saw it again on DVD recently, the impression wasn't that great this time. This film is meant to been seen on a big cinema screen.