Blizzard have just announced World Of Warcraft: Legion at Gamescom2015 in Cologne, Germany. In a livestream event Lead Designed and VP Tom Chilton unveiled a teaser trailer and some additional information, including a new Hero Class and raising of the level cap to 110.
The story, as outlined in the post-unveiling developer discussion, follows the aftermath of a Demon invasion of the Broken Isles continent of Azeroth which will begin in the dying embers of the Warlords of Draenor expansion. By playing the game you will uncover the last acts of Illidan and the Demon Hunter Illidari, recruit them to your cause, and push back the Legion.
More information, as well as the official CG trailer, are likely to be released in the coming months. A parting comment by Tom Chilton hinted that the Legion Beta will begin later this year.