An email leak from the Irvine offices:
Expansion Details:
Name: Rise of the Naga Empire Main Villians: Azshara, N'zoth Plot: The Burning Legion has diverted the attention of the heroes of Azeroth away from their home lands. As the war wages on Argus to stop the Legion, Azshara continues her preparations in carrying out the will of N'zoth by readying an invasion that will cover every continent on the planet. The Naga Empire has been building its forces and patiently waiting for the perfect time to strike. Using a twisted form of black magic and power granted to her from N'Zoth, Azshara will carry out a ritual that will cause the submerged Naga empire to rise from the depths. Both the Horde and Alliance are unprepared for such an attack, and as a result, many iconic locations will be destroyed. In order to defend the lands that the factions of Azeroth hold dear, both major factions must band together even amid the hatred both feel for each other.
Inventions created by the Gnomes and adopted by the Goblins will be created and refined to help curtail the invading Naga. Gifted and mechanically intelligent Gnomes and Goblins will pilot massive suites of Armor and will be instrumental in holding off the Naga invasions. These Tinkers will be looked at by the rest of the horde and alliance as essential to the military efforts that will greatly help turn the tide of battle.
Major Expansion Features:
Level Cap Raised to 120
New Race: Naga (Neutral) A splinter faction of Naga unwilling to succumb the Old God's whispers defect from Azshara's ranks and choose to either join the Horde or Alliance
New Class: Tinker (Gnomes & Goblins) Tank, DPS specs available.
New Neutral City: Undermine
New Mount Type: Boats (with the help of the Goblins and Gnomes, players will be able to create their own boat in the initial leveling stage of the expansion. Faster boats will be able to be found as mount drops off bosses.)
Race specific House Boats will be able to be created and customized by players.
Faction Allegiance System: Allows horde and alliance players to undergo a series of quests and events that eventually allows them to group together, unlocks account wide.
8 New Zones (All new zones will have Legion level scaling tech except for ones indicated):
Leveling Zones:
Scintal Reef (Naga Leveling Zone 1-20)
Kul'Tiras
Isle of Kezan
Zandalar
Tel Abim
Drowned Reaches
Max Level Zones:
Gishan Caverns
Nazjatar
Other Major Features:
2 New Battlegrounds
1 New Arena
3 New Raid zones available at launch, more planned in several patches
12 Dungeons available at launch, 10 New, 2 being refreshed previous expansion dungeons, more planned in several patches
Transmog Closet updates, to include all off set "sets" (example purple paladin tier 2 BC dungeon set)