Yeah i'm always looking forward to new peripheral devices. Unfortunately most of the developers are not gutsy enough, or try to bandwagon too much without coming up with their own devices. The wiimote enabled some awesome applications like these (http://johnnylee.net/
) and there's obviously a lot of interesting kinect hacks and fun ways to exploit it like using it to create a 3d pointcloud from its data to simulate AR and other things. (*cough* occulus rift *cough*)
But all those things will mostly remain toy's to developers and not evolve too much for now i dont think.
Touchscreen is probably the worst thing that could happen to gaming. It plays perfectly into the current dumbing down
of games, because it restricts input so much, you just cant make complex games with it. Its clunky, inaccurate, you obfuscate your own vision. It's just nothing a gamer would really want.
Since it works 'fine' (well enough maybe) as input device for a mobile phone there's not much incentive to develop it further or *gasp* add buttons to the phone.
As far as input goes for accuracy and speed there is currently no equivalent to the mouse and keyboard setup, so i dont see gamers letting it go; but gamepads do have their place for certain genres, aswell as joysticks. There are even some games that work decent with touch screens, like a tower defense would, or slow paced/turn based rts maybe.
A game can only be as complex (i.e. good) as its means of control.