It seems quite obvious to me that Blizz will make another VoA boss in 3.3 aswell, this one being based on the water element. Two things you can discuss is: First of all, where would they put the boss, since there's already a path in all directions. Second of all, how would the fight be?
My guess is that with the placing of the boss they either move the entrance so that you enter in the middle circle and make the water guy be in the end of the south path, or they arrange it so that when you've defeated all the three other keepers the middle circle will open up and allow you to jump down in it and land in water, and the boss would be placed either below you or at a shore not far away.
The fight however I think either Blizz will actually make it an underwater fight, wich they've been thinking about making, or the fight is on land with Ice-theme, for example blizzards, frost novas maybe even an aura a'la hodir, or pools of water along the side wich play a role in the fight (if you get a debuff, run to the water etc)
Discuss
Edit: Forget the elevator, seems they're going to put it in a pretty fail place imo :-\