I think the screened controller should stay. Not in its current form, but more like a gamepad 2.0.
add multi-touch, add some level of processing power, add a 3DS player, maybe a slightly higher resolution screen.
I'm not sure 4 gamepads would ever be needed, or bought in the same household w/ only 1 system, but support for 4 could never hurt, even if we only ever use 2. There is alot of potential in a controller with a screen in and out of gaming usage.
My ambitions for the idea lay mostly in the non-gaming applications, but I'm sure there are plenty of uses in game, especially for head to head competition gaming, like FPS and Sports. a lot of the in-game uses may seem gimmicky, but they could also be immersive, and we have threads with game ideas using the game pads so I won't go too deep into that.