The central trio of Harry, Ron and Hermione is cute. I wish, though, that Ron would really grow up - if that shrieking around like a banshee continues, he may well play Hermione's part in the next flick. But Harry remains as wooden as ever. Am I missing something or is this bloke meant to be this way? He just doesn't have enough chutzpah to carry off the role.
As far as sequels go, I suppose this bit falls neatly into the groove made by its predecessor. BUT UNLIKE
The Two Towers, wherein the sequel created a canvas that enlarged the scope of the movie, Harry Potter continues to work within the narrow confines of the world created in the first bit. There is nothing terribly new or expansive in the sequel. It almost falls flat in terms of adding to the original. It might be great for folks who want to keep up with Potter, but hey, I want to see something new - perhaps something that I wouldn't expect in a Potter flick. But I suppose the filmmakers, bound by the book, are confined in terms of expression.