We have a few solutions on the PC side of things to stream games from a computer to another display. NVIDIA's Shield is one example and before that we had Splashtop THD, which let gamers stream their games to a Tegra 3 Android device. You'll soon be able to add a Wii U to that list.
30c3 is a group of hackers that successfully reverse engineered the way Nintendo streams games to the Wii U controller. While the demo showed off the early stages of the application with it crashing, the team plans on a more user friendly way for others to use the program. For now, developers can take the code and see what they can do with it. To demonstrate the program working, 30c3 streams The Legend of Zelda: Wind Waker that's running on the Dolphin emulator to the Wii U controller.
No lie, I started to think about picking up just the controller when I saw this. I can't wait to see the program released for general usage and try this sucker out.