Zarhym notes in his tweet below that it was made for internal purposes, and we're glad they're sharing. Of course it's not as polished as something we'd see at BlizzCon or as a trailer, but it's still pretty good.
Have a look! And this just reinforces my happiness over the revamp of Scarlet Monastery.
The devs shared this video a while back w/ all at Blizzard to get us pumped. Loved it so much we had to share w/ you! bit.ly/NDqdR5- Zarhym (@CM_Zarhym) September 20, 2012
It's open warfare between Alliance and Horde in Mists of Pandaria, World of Warcraft's next expansion. Jump into five new levels with new talents and class mechanics, try the new monk class, and create a pandaren character to ally with either Horde or Alliance. Look for expansion basics in our Mists FAQ, or dig into our spring press event coverage for more details!