While we're waiting for the beta of the next World of Warcraft expansion, Warlords of Draenor, Blizzard devs shared an in-depth video about upcoming changes, including PvP, class skills, and a new world PvP zone, Ashran.
It will be a savage, ancient Ogre island, with similar game mechanics to Timeless Island in Mists of Pandaria. It will have Horde and Alliance fortresses on the opposite ends, with NPCs and vendors, and a huge battlefield outside the bases. The main battle will take place in the center (with tons of quests all over the place), slowly pushing up and down the main road towards either faction's fortress.
Here are some work in progress shots of Ashran from the video. It looks really promising, hopefully they fill it up with a lot of good stuff: