Good action, good-hearted film. A little predictable, but without giving away the ending, I did enjoy it. That was the only thing that was not as predictable. I really liked the message it conveyed.
This is one of the few later movies (after 1 and 2), that actually stayed to the book pretty well. I think it left out some key items (the beginning scene was not in the book and not necessary), but I think the assumption is that most people have read the books before seeing the movies.