It's pretty good, especially if you keep in mind it's a comic book movie and not the second coming of Citizen Kane.
digex and I saw it Saturday night at the Uptown, which is really the only place you should see it because only the humungous wraparound screen doe it justice.
Spoilers behind the cut.
It's pretty much the story promised in the trailers, with a lot more blood and thunder and a plot lifted from Batman and Spiderman. You can see the file marks where they took off the serial numbers. Despite all the violence (and there is a LOT of violence) there's some humor of the non-Schwartzenegger quippy sort, an amusing subplot about the title character's relationship with one of his classmates (she thinks he's gay), some excellent music (including a horribly appropriate Joan Jett number during one of Hit Girl's fight scenes), and an ammo budget that probably exceeded what they spent on The Matrix. Lots of fun. Metro ride to and from, not so much, but that's life in the big city.