I don't like how people are comparing the expansion to Kung Fu Panda, as if that is all panda's ever represent. Personally I think it's too early to really speculate and I will approach the expansion with an open mind. I am looking forward to a bit of chance in pace compared to the old "your doom is coming from this bad badass somewhere in Azeroth".
If you actually read up the story behind the Mists of Pandarea the lore between how the two Panderan factions split apart to join either the Alliance or the Horde, as well as the new content that is being discovered yet that was there all along.
I also think it's about time that Alliance got the more sinister of races and horde got another more gentle/less violent one.