Pokemon MMO...I mean you already have starting cities, a system setup for tournaments, hundreds of creatures with a LOT of strategic choices. Not to mention, if you cross platform it, DS, consoles, mobile, and PC, you can play anywhere and take your Pokemon with you to battle someone you randomly meet. That or a Blade Runner-esque MMO. For me, it's hard to come up with a new KIND of game, but far easier to find characters/genres/heroes who deserve to be in the spotlight. A Phantom 2040 game ala Arkham Asylum style fighting or a space sim where multiple people control different classes who operate one giant ship and have to work together in order to survive. I'll stop dreaming now.