I saw it this weekend, and I liked it a lot. It's not perfect by any stretch (there are a few plot holes and silly decisions), and it's clear that this is the first movie in a trilogy (not a ton happens that's of any real substance), but I thought it was interesting enough, and the action was great.
I'm not always a huge fan of "spectacle" movies (I hated Transformers and X-men 3), but this was worth seeing in the theaters.
(My girlfriend, though, didn't enjoy it, although she thoughts some of the robot special effects were cool.)