They told some cool stories afterwards but it was kind of spread out. The rise of Wrathion from the Badlands quest to the Rogue legendary questline housecleaning was outstanding. Taran Zhu's arc in pandaria was cool to watch. The fate of the Zandalari in Pandaria was unexpectedly tragic. The search for the hidden master and the defense of Stonehearth is one of my favorite lines in Mists. The corruption, liberation and fall of the Klaxxi was really well done.
There's nothing quite like Arthas. They aren't going to build up another big bad like that, ever again.
Valley of the Four Winds was fantastic