Joke

 Everybody is waiting for it, may as well do it... even though I think reality is far funnier than fiction this time.

I think Pandaren fit right there in WoW, and this is exactly the problem. After stretching and modifying the lore so much, anything can really fit there. Kung Fu Pandas aren't worse than Space Demons or Werewolves. May as well put robots and murlocs on the next one.

With Pandas I am sure there will come a whole host of racial enemies like mantis and monkeys which you will mercilessly kill but ultimately, will not advance the plot.

WoW's world keeps expanding, but there is little closure. It gets wider, but not deeper. Deathwing was a step on the right direction but was just that- a step, and there are miles ahead of plotlines to tie and finish.