Half-Blood Prince is essentially one long prelude to the events coming in Book 7. It sets up crucial plot points. I thought they did a great job of turning a not-very-action-packed chapter in the HP series into an entertaining movie. I liked it a lot. The ending left me wanting more, and that's a good thing. "Deathly Hallows" (the big finale, which is being split into two movies) is by far my favorite book in the series, so I'm excited. The filmmakers have proven that they know what they're doing and the actors have grown into their roles. It's one of those rare series that actually gets better and more mature as it goes.