The tactile/haptic feedback is a good point/addition but the reality is that for gaming applications that require those features, users will always spring for a real controller (and should - touch devices wont kill all things, they'll just replace those use cases in which haptic/tactile feedback isnt critical). I'm working on bit.ly/watchandplay which is similar but more of a user first product (rather than developer first) and I think the real potential here is to connect every internet connected screen to the phone as controller, so that you never have to lean forward again.