You already know how we think the Steam Controller will work with your favorite genres. Now Valve has posted a video which shows how the adaptable gamepad handles four very different games: Portal 2, Civilization 5, Counter-Strike: Global Offensive, and Papers, Please.
The dual trackpads can emulate a mouse or serve as a sort of D-pad-joystick hybrid, depending on which works best in any given game. The pads and all the buttons can be customized to represent keyboard and mouse commands, and Valve plans on providing recommended layouts for popular games which don't support the controller natively.
The hardware's still in beta, and it doesn't look any less strange, but it clearly works--what do you think of Valve's first step in shaking up the rigid world of video game inputs?