That's what was so great about the story of MoP! Up until Mists, the Horde and Alliance were fighting each other non-stop with no outside of opinions. Then the Pandaren are introduced and thrust into this war they had no choice but to be a part of because of the faction's blind hate for one another. It offered an outside perspective of just what kind damage the faction conflict has and the lengths both were willing to go in the name of conquest and victory. The Pandaren were victims of the Horde and Alliance's pride and malice.
The Klaxxi! Man, I looooooved the voice acting of the Klaxxi and the Paragons! A mix of eerie and malicious. Heart of Fear and the Paragons in Siege of Ogrimmar were scenes where I made sure to listen in to the dialogue and sounds.