Sorry to double-post but I remembered something I wanted to say. Ashaya reckons that the Qyburn-Mountain scene wasn't finale material. While I do agree with that statement, I think that is was essential to still have that scene when they did. They needed to show that the Mountain was in fact still alive, but that he was suffering, and that he was poisoned by Oberyn. I know many show fans were wondering at the end of episode 8 whether the Mountain died or not, and I think it was important to let fans know that Gregor's still a player, but also to show that Oberyn knew what he was doing. I think if they waited until season 5, it would have been out of sight/mind for too long.
Fan: "Why do you keep killing off all the characters I love?!"
George: "Perhaps you love the wrong characters."