I didn't think there was anything wrong with the ending of the new Hobbit movie. It's the second out of three, so you have to know it's going to end on a cliff hanger of some sort. The whole movie is basically meant to set up the third movie. Anytime someone makes a trilogy the second movie is always a bit of a let down because it never stands on it's own as a complete movie. Any planned trilogy I can think of has followed that rule. You just have to remember that going in and accept it as it is.
And yes, the dragon looked fantastic. I wish they had put as much time and effort into the fight scene with the barrels in the river as they did into the dragon.