Move aside all you Demon Hunters, Tinkers, and Bards! This is... THE SAGE!!!
The Sage will be a hero class that starts at lvl 80 with it's own starting zone, underneath Karazhan! The spirit of Midivh which is trapped below Karazhan has called some braze souls who already have some skills for magic to join him and train below Kara to become Sages. Medivh being the last Guardian of Trisfall, is a master of all forms of magic Shaman, Druid, Mage, Priest and Warlock! With his training and teaching you too can become almost as powerful as he by combining all the magics into it's own unique style! Here's more information on Medivh...
http://www.wowwiki.com/Medivh
So you start off at lvl 70, and wear cloth for all 3 specs. The specs being...
Twilight- A combination of Holy and Shadow to deal shadow damage to enemies and to heal party members at the same time, using dots and once the dots tick their final tick they heal small amounts to the party.
Frostfire- A combination of Frost and Fire ranged damage. Mostly of cast times and direct damage with lots of control.
Groundwater- A combination of Nature and Water healing spells. Plenty of Hots and direct heals.
Once you do some starter zone quests and finally get to level 80 you go out unto Cata zones leveling up to level cap as usual with some Class quests mixed into the leveling Process. At 85 you would have a class quest to learn Travel Form where you would turn into a version of your racial mount, where other players can ride you. At 90, you would have a quest to learn Flightform. At 100 you would learn mass teleport, and mass summon!
The Sage will be balanced with other classes, the reasoning is because while other spell casters such as Mages constantly grow and level up and improve, The Sage will be trying to be a master of them all, but never coming close to the expertise of them, but still powerful using all different types of magic. Let me know your thoughts, please no comments like "No new classes" if you feel that way you shouldn't be clicking on a new class theory, it's not constructive to the topic at all.