I saw this Saturday with some friends. The previous movie sees the return of the death eaters and Voldermort in the open.
The story revolves on Harry viewing his role as "The Chosen One" as his own. Of course, with all the plot lines, this is hard to catch. And, he has that teenaged I-am-special-if-only-everyone-else-could-figure-this-out world view. At least he does in the book. The movie has Dumbledore understanding perfectly how wonderful Harry Potter is, although he is apologetic about demanding so much of him. In the book this is also true, but I don't remember Harry being quite so understanding of things.
The films still suffer from too many plots going on at once. This sort of thing works out better in books, in films it gets confusing since some characters are doing double and triple duty.
I remember not liking the book so much, because the Harry Potter teen-age angst was in full form at this point, with very little redeeming virtues. But with this watered down for the movie, it is harder to figure out his motivations. Or motivations for many of the other characters (ok, all the girls in potions class are pretty easy to figure out, but lots of other people seem pretty random if you had not read the books.)
Oh, the major character development plot seems to be all the kids starting dating, and it has to be with major drama. Again, this part did seem to work out better in the movie then the books, but it still seems compressed.