If you have not seen the video yet it's here: http://www.youtube.com/watch?v=8GLgI17_IK4
So the warlocks or more specially Council of the Black Harvest are very interested in empowering themselves with the powers of Deathwing, Cho'gall and Ragnaros.
For more information about that see: Legacy of the Masters (Part 1)
Now the Deathwing's Lair that was absent from TBC is still somewhere floating around since the Nether Drakes hatched after the destruction of Draenor.
The video of the Warlock Island shows a dragon lair through merely a copy of Maw of Neltharion it could be the lair.