"New rumors are coming in about the next World of Warcraft expansion, and yet again they involve the continent of Northrend. It's very important to keep in mind that these are just rumors right now, but there has been a feature list found(in German - presumably for the Games Convention in Leipzig) as well as a FAQ. The FAQ is in English, and I've pasted some of the more pertinent pieces below. You'll want to check out wowszene.de for the full FAQ.
Features
The continent of Northrend added to the world of Azeroth. Northrend is about the size of Outland.
Content for players level 68 and up.
Level cap increased from 70 to 80.
Brand new abilities and talents introduced.
New "Hero" class added - the Death Knight; this class will need to be unlocked through certain criteria before it becomes available.
New Profession: Inscriptions - allowing you to permanently enhance spells and abilities.
Siege Weapons and Destructable Buildings added to the PvP landscape, as well as a new Battleground.
A plethora of new Dungeons, including 25-player Raid Dungeons and Heroic variants.
An abundance of new quests, monsters, items, and recipes. " Article can be found here
