If we make something similar to TAO what sort of theme would be appealing?

A Game of Thrones-y vibe (knights, archers, zombies, dragons, witches, nomads, etc)
A Pirate vibe (swordsman, knives, rifleman, canons, voodoo witches, seamonsters, etc)
A Risk like vibe (multiple unit clusters on a map like board, moves like an entire army in board game-y fashion)
A storyline based fantasy game (community driven/written storyline as storyline develops new unit introduced/removed to keep strategies fresh)

Something else? Ideas?