If you want to find an event near to you, the official site has an events page that will be of use to you. For US residents, the official meetup in California is at Giant Wheel Court at the Irvine Spectrum Center, 71 Fortune Drive in Irvine at 9:00 p.m. PDT on September 24.
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!