For those who didnt see the Ulduar intro yet. Jaina and Rhonin the master of Kirin-Tor trying to get Aliance and Horde together against old got Yag-Sharron which dwell in Ulduar now, but Thralls friend Garrosh and King Wrynn, will mess up this aliance because of they hate and rage...
So is up to us, players, banish old god one more time from Azeroth...
https://www.youtube.com/watch?v=Vjb0EaC80W0&feature=fvw