8CN: A Valve patent for a "video game controller having user swappable control components" has been discovered. The design would allow for modular components to be slotted into different sockets, allowing for "dual analog sticks, a combination of analog and trackball, or further any combination of touchpad, directional pad, or additional components."
via N4G: pc news feed http://n4g.com/news/1360663/valve-patent-for-a-customizable-controller-found-is-this-the-day-2-announcement
via N4G: pc news feed http://n4g.com/news/1360663/valve-patent-for-a-customizable-controller-found-is-this-the-day-2-announcement