I think that this expansion comes in 2 parts. in the first part you are able to lvl 85 and there will be 1 new mayor raid, maybe uldum and some recycled vanilla raids. In the 2nd part you are able to level to 90 and go deeper into the maelstrom, where you will meet Azshara, Deadwing and possible another old god? oh, and another few recycled raids ofc!