Live from Blizzcon, It is:

Mists of Pandera

• New Playable Race -- Pandaren: Adventure through Azeroth as World of Warcraft's first neutral race and decide whether to side with the Alliance or the Horde.
• New Playable Class -- Monk: Unlock the secrets of pandaren martial arts and do battle as a damage dealer, healer, or tank.
• Level Cap Increased to 90:Learn potent new spells and abilities while exploring uncharted zones and taking on challenging new content.
• New Zones:Explore the lush Jade Forest, treacherous Kun-Lai Summit, and other exotic areas of Pandaria designed for high-level characters, and uncover the mystery of the Wandering Isle.
• Scenarios: Join up with some friends to achieve a common goal, such as mounting a defense against invading monsters, in a flexible new type of PvE challenge.
• Dungeon “Challenge” Modes: Master the ultimate five-player time trial to earn prestige rewards in a new dungeon mode that will put your resolve and coordination to the test.
• Pet Battles: Challenge other players’ companion pets with your own collection in a new tactical mini-game, and find out who's king or queen of the pint-sized battlefield.
• New Talent System: Customize your character to suit your play style with the newly overhauled and improved talent system.

Other news, if you subscrib to Warcraft for a year, you get Diablo 3 Free ( while subsciption to Warcraft contunes )

You also get Tyreals Sparkle horse.

Updates:

Metzen announces that both Alliance and Horde can be Panda's
During the Opening, they say they are bring the War back to Warcraft.
Loads of talk about Red Vs Blue