That's actually a very kewl idea! Why not patent it right now! lol. I would guess with wifi and/or USB input, there could be a way to plug it in and use it. Basically you could provide a driver (possibly) that runs as a service that can take the buttons you press on the controller arms and send them as keyboard keys as if you pressed the keys. This way a user could configure the controller for a specific game, perhaps. I don't know that any game would be written to use any 3rd party controller tho.. more likely games should allow configuration of keys that control avatars and such in the game.
Honestly the only game from iphone I miss is ragdoll blaster... Madden 10 was an ok game but I never liked the controls. I think you give enough time Android will surpass what there is to offer on itunes.
Coming from an iphone and a storm 1 (ughhhh yes) I am happy just to have a phone thats actually usuable that has the promise of games.
imo iphones was jack of all trades master of none..