Varian is being set up to die the second Anduin gets an adult model imo, give it 1-2 more expansions, and then maybe Blizzard can play around with his rationality from the comics being shaken from unsuccessful ventures for diplomacy with the new war-oriented horde. I also full heartedly believe that Sylvanas is getting replaced by Lilian Voss, solely on the premises that Sylvy was proven vulnerable in the Silverpine quest chain in cataclysm, and that Lilian is an shadow ascendant, which is like a top tier Forsaken, which fits the niche's that all the other current faction leaders sit in. Varian is a super 2man strengthed human warrior, the same could be spoken of Garrosh, Tauren's are rockin Bloodhoof with his dual totem chieftan goodness, arch druids for the Nelfs, etc, etc. The only one who doesn't really fit the bill is Sylvy, who is in a sort of honor position for stepping up to get the forsaken a place to live, and she is totally startin to be mega douchey.