Just got back from it (saw it on the IMAX screen), and I really enjoyed it. Great eye candy treat for anyone who's read the graphic novel (some really graphic violence, especially when Dr. Manhattan's killing). The music selection was really good, such as the "Ride of the Valkyries" for when Dr. Manhattan was taking out the vietcong, and "Hallelujah" for Nite Owl and Silk Spectre's love scene (haha, both scenes gave me a good chuckle). The only thing I didn't like was My Chemical Romance's cover of "Desolation Row" for the credits, that was just all noise, they should have stuck with the original.
Something that really struck me was how Jackie Haley's Walter Kovacs looked so much like his comic/novel counterpart, it was dead on IMO, like straight from the pages. The only thing that bugged me was how he kept with the Batman voice after being unmasked. I was kinda expecting him to play down the voice a little when he was Kovacs. But then we're told/reminded, that Kovacs was no more when he found the dead little girl, which I guess kinda explains why his voice stayed consistently that way.
Regarding the ending
They trimmed/altered/omitted quite a few things, such as that whole little side story with the pschiatrist (him becoming more and more obsessed with Kovac's), as well as the thing with the newstand vendor and the kid with the comic (but I've read that the plan is to re-edit this part, along with the Black Frieghter segment, back into the movie for the DVD release). The killing of Hollis Mason was removed as well (hopefully it's added back too). I can understand why they did it, but would have been nice to included it as well.
Now I wanna read the novel again, to see what changes were made.
Jam it back in, in the dark.