This expansion focuses on the clash between the Alliance and Horde forces on Azeroth, but who do you think will end up the final tier villain. As far as i'm aware they haven't announced it, as they haven't the last couple expansions. I know Queen Azshara is suppose to be a mid-tier boss I believe I heard. So I almost feel as if N'zoth may be the final tier boss if it continues with the Naga story-line route, but may save him for a future expansion. Could refocus the story later on with a faction leader becoming the final boss like MoP. Or possibly our own titan could end up the villain, although i feel that's doubtful.
As a side note. Blizzard, I feel has been setting up new character to replace ones who were defeated through expansions. Bolvar the new lich king. Wrathion possibly a new Deathwing in the future. Sylvanis seems to be pointing toward the Garrosh path. Our titan could end up the next Sargeras in a sense from the Corruption of the old gods, but of course not with the same goal if that were the case. Magatha the new twilight hammer leader, etc. Any others? To continue stories in the future to build upon. What do you think for both? Would love to hear thoughts and theories.