Spoiler:
In the book, most of the "bad" kids were permanently disfigured at the very end. Augustus and Mike were both stretched out, and Violet's skin was blue. (Veruca was covered in garbage, but it's not like you can't remedy that.) In the movie, Wonka does make reference to them being stretched and whatnot, but at the end when Charlie asks what happened to them, he says that they were "restored to their normal, terrible selves" but hopefully "wiser for the wear". I thought this was a much better message than fucking over the brats for the rest of their lives.

In the movie, a mysterious competitor named Slugworth approaches each ticket winner and offers them compensation if they bring one of Wonka's mysterious Everlasting Gobstoppers. At the end of the movie, Wonka deliberately rebuffs Charlie and his grandpa. Saddened, Charlie puts the Gobstopper on the desk and turns to leave. It turns out that this was a test, so Wonka now entrusts him with the factory. In the book, Charlie was the only one to make it to the end of the factory and Wonka said that he was going to give the factory to whoever he liked best - no acid test of character was required. In this scene, Wonka's office had lots of otherwise normal objects that had been cut in half, like a sink and a clock - a creative touch that gave us more of an impression of his eccentricity and that was not mentioned in the book at all.

There were other differences that I thought the movie handled better, like Veruca's demise (doing a song and dance and unwittingly winding up on the egg judging thingy and being dumped into the garbage as a bad egg seemed much better integrated into the scene than having a bunch of squirrels throw her into a hole in the ground), but this post is getting long enough already, so I'll save 'em for later.

Spoiler:

Spoiler:
Ah...I don't remember the bad kids in the book being quite as annoying to me. I was surprised that Veruca seemed nicer than she did in the first movie (in which she really was an insufferable little brat ). It looks like I'm just going to have to go reread it. In any case, I hope the movie goes all out with the darker tone, bringing the most grating aspects of the naughty children's personalities to life so everybody can revel in the schadenfreude as well.