It's commenter Buffalo's birthday, and as is Queue tradition, we wish him a happy one today.
Do you think we will ever see further exploration of the elementals and their lords? We killed Ragnaros and Al'akir within their own plane, permanently ending them, so wouldn't another, suitably powerful, elemental step in to fill the void? I think it would be neat to come across the new Lord/Lady of Fire or Air, possibly assisting them in their attempt to cement their rule, or defying their bid for dominance.
Plus, Neptulon is still circling the drain.
I wouldn't expect news of a new Elemental Lord any time soon. Cataclysm was sort of the Elemental Expansion and it's likely going to take millennia for an elemental to rise where Ragnaros and Al'Akir fell. Besides, we killed pretty much all the big-name elemental lieutenants, too.