Myself, I'm completely torn (no pun intended) between a Giant Stompy Robot game or a Dragon based game.
Lair could well turn out to be the game I would have made. Which would be both amazing and just ever so slightly creepy.
An RPG set around Macross or The Invid Invasion with mile long ships and huge mecha combats. Lots of open ended pathways where even your most innocuous action could have huge consequences. Nothing so basic as choosing good or evil from a menu.
As for who would do it. I'd have to think on that.
Have to be on the PS3 no other system would have a large enough storage capacity.