Reader Chris is doing the world a great service with his work transforming the Wii U's big pad into something you can use on a PC.
The video above shows how you can re-map the pad to almost everything needed for a game's input, meaning if you can configure it, you can use it for most contemporary titles as well (or, say, the Dolphin emulator).
Chris tells us the first pending update will add touch-screen support to the pad, while in the future he's also working on getting streaming working, so that you could play a PC game on the controller.
You can download the necessary files here