Most notably, SHIELD can stream your gameplay between itself and a nearby gaming PC, where it utilizes the PC for rendering tasks and streams video. The company said:
"Most PC gamers own a fairly sizabl games library. But unlike music and video which can be streamed freely around the house, playing PC games requires sitting in front of a PC. Even if the picture could be streamed, where would it stream to and how would one interact with it? SHIELD elegantly solves both problems. With a 5” 1280x720 screen and a full sized controller, it is capable of not only displaying a PC game in its full glory, it lets you play it too. And because the rendering is done on the PC and the picture is streamed as video, you get GeForce GTX class graphics and long battery life. It’s kind of like having a GeForce GTX PC in the palm of your hand combined with the battery life of a Tegra device. "
The device is expected to ship in Q2 of 2013. We will have further information on the device as the show goes on.
Read more here: http://www.geforce.com/whats-new/articles/nvidia-project-shield