As initially stated by Bashiok and confirmed by J. Allen Brack, production director of World of Warcraft, you will be getting an 11th character slot for your monk. Players without the Mists of Pandaria expansion attached to their account will be restricted to only 10 characters. You must upgrade to Mists for #11.
Rejoice, fellow nerds. Rejoice.
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!