When WoW's Burning Crusade expansion was announced at the inaugural Blizzcon in 2005, a suspiciously large number of magazines that had been invited on tours of Blizzard HQ reported that the expansion would add the Pandaren to the Alliance. The Horde Blood Elves were both confirmed and playable at the convention, but the Alliance race was a mystery and there was no information anywhere in the public record to support this claim. The rumor is that Blizzard was planning to add Pandaren, and even showed the journalists concept art, but subsequently reversed the decision because of concerns that China would disapprove. Blizzard confirmed the China issues back at Blizzcon 2008.
Having actually visited a random village of walking Kung Fu Pandas, hidden deep in the mountains of Odus, I'm now wondering that China may have done Azeroth a favor. The space goats that we got instead may have been a bit random, and required a re-writing of a major chunk of Warcraft lore, but they actually fit into the storyline of the expansion in a way that I don't think the Pandaren would have.
Don't get me wrong, walking talking animals are reasonably well established in Norrath, which has giant frogs, rats, and cats amongst its playable races. That said, the secluded dojo of somewhat pacifist martial arts pandas, complete with tea ceremonies and bamboo architecture, is a bit goofy for player characters, even for EQ2. (There's apparently a cosmetic illusion that lets you turn into a Panda, so that bit of abuse is probably in Lyriana's future at some point down the line.)