Steam Controller design, eradicating the center touch-screen in favor of a more familiar physical button-based set-up. The image above came from folks on Twitter attending Steam Dev Days today.
Valve decided to add the buttons for backwards compatibility purposes. The controller's signature trackpads, however, remain untouched. Considering the controller is still in beta, we wouldn't be surprised if the Steam Controller gets another facelift before its official launch later this year.
[Image credit: @TheIneQuation]