Saw this last night and whilst i think the whole thing is a great (and often exciting) technicl achievement, its also (bar a couple of moments) totally devoid of originality and ultimately, very pretentious. This is a movie that will be forgotten very quickly as it is, already, a victim of its own hype-machine.
Its also possible it could become the victim of a lawsuit. There was a great little film made back in 1988 called 'Miracle Mile' starring 'ER's Anthony Edwards as a young man trying to rescue himself and his first date from a potentially imminent nuclear strike on New York. 'cloverfield's big monster feet tread a very, very similar path to the one trod in this 80's gem, so much so, that Mr Abrams had better have a good defence team waiting in the wings should the lawyers come a-knocking on his desert island retreat front-door. I recommend you check MM out on IMDB now if you either loved/hated Cloverfield, cos its an ace movie thats worth tracking down.