He's using a smartphone and a wiimote to communicate the motion of his arms to the motors powering his kite-material wings. Follow the whole project at HumanBirdWings.net. Get a better understanding of how the phone and wiimote are working together here and here, and this video is useful for seeing the communication with the arms and the motion of the motor-driven wings.
The press coverage I've seen for the project has been more hopeful than evaluative, so you should still prepare to have your heart broken when the big hoax is revealed, but for now, start thinking about the plan for a flight path near you.
UPDATE: Ok, that's enough fantasy for one afternoon. Gizmodo brings the rain to the parade. (Thanks Ali)