I don't want to see one class go from situationally okay to unplayable. Priest is the worst class in the game. It wins the fewest games and relies on gimmicks that don't swing the tempo very well EXCEPT for mind control and the shadow words.
It's a weak, slow class that tries to outlast opponents, but is not a true hard counter to anyone. It's win-rate is a paltry 43.67%.
According to this, Warlock needs a SLIGHT nerf and priest needs to be BUFFED like crazy.