Daniel Evans, on 15 October 2012 - 10:38 AM, said:
I actually found that leveling as Discipline was more life saving due to the fact that there are vast amounts of trash mobs during quests.
(i.e. Packs of two to four monsters which are not necessary for your quest but are in the way of it.)
I tried Shadow and died numerous times.
As a shadow priest, I am not having any problem leveling in Pandaria but then I'm only at level 87. No death issues yet. Disclipine may indeed be an option at higher levels.