First off, the opening credits cut right to the chase, and as the music is still playing, you get that Bruce Banner is the Hulk, and he's on the run. This really lets the story get going right away, and even if you missed the Ang Lee/Eric Bana movie from 2003, you still get it. It was a smart move, and really kept the audience into the film.
The next thing that worked well was something that I was really worried about, and that was the casting of Edward Norton as Bruce Banner. I thought he'd either be too deep or play it too pathetic, but he really seemed to play Banner the way that I read the character as being in my favorite comics. Nervous, but responsible, and just driven enough to keep going. He was a great Banner, and he gets my kudos for it.
The Incredible Hulk also picks up where Iron Man left off, and really sets itself in the Marvel Universe. As the Army gets ready to chase Hulk around, weapons and schematics are labeled with "Stark Industries" and documents and references are made to SHEILD. The last scene of the movie, which I won't spoil, also made sure to make the fanboy in me salivate.
The movie also borrowed plots from the comic books, taking elements from both
Bruce Jones' run (Banner the fugitive) as well as from The Ultimates (Banner working on the Super-Soldier serum) and this really made the world more cohesive without pulling non-readers out of the story.
All in all, the movie was a success for me. The cast was as good as they had to be, the action was clear, Hulk smashed the Army and the Abomination, and the movie left the door open to introduce Doc Samson, The Leader, or tie into other things without weakening itself as a stand-alone. If you liked Iron Man, you'll like Hulk too.
My pal Keith was nonplussed at my recounting this fact, saying "He's a big, muscled guy who rips out of his clothing and runs around in his underwear." which of course leads me to believe Keith has never really known any gay people, or if he has, has known very scary and odd gay people.