As a onetime owner of a Magnic Light, I can assure everyone that it is real, it works, and works pretty well. (I also wrote the review linked above.) It isn't magic as the name implies, but it does use a different means to generate power, one that you wouldn't expect.
The movement of ANY conductor generates eddy currents. In this case, the aluminum rim of your wheel is a rotating conductor and it generates the current. The magnets inside the light then move to generate the electricity that powers your lights. This works even though the rim is non-ferrous.
The real engineering feat here isn't the "magic" of the eddy currents, it is harnessing them in something small and light enough to put on a bike.
Look at the video on the
kickstarter and you can see how this thing is built.