In other WoW news from the call, Blizzard has renewed its license with NetEase for China distribution: "On March 20, 2012, Blizzard Entertainment announced that they renewed their license with NetEase for the distribution of World of Warcraft in mainland China. The new license will continue for an additional three years following the expiration of the current license agreement."
There is no indication of specific North American / European numbers, nor is there any specific indication of when Mists will release.
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!