This is used in the mag-lev trains and many of the newer roller coasters, however, an electrical power source is required to set up the magnetic field that pushes against the stationary field.
Actually there is only one set of windings producing a magnetic field. The track consists of a series of coils which is energized by three phased electric current (much like a three phase induction motor except they are laid out flat along the track rather then in a cylinder for a rotary motor). The car has aluminum fins just above the coils. When the coils are energized they induce an electric eddy current in the fin which also generates a magnetic field that interacts with the moving field in the track. The resultant forces both levitate the car out of contact with the track and propel the car along the track following the poly-phase magnetic wave (something like a surfer riding a wave in the ocean).
The car needs no built in magnets nor electric coils, all power is supplied by the track, further, only the coils directly under the car need be energized to propel the device. The frequency at which the coils energized determines the speed of the car and by reversing the phase shift sequence you can produce smooth braking without mechanical contact.
Regards,
GtG
PS The device pictured in the Australian video clip has been around for at least five years, if anyone had/has figured out how to produce a mechanical device with a coefficient of performance greater then 1 we would have heard about it by now. Contrary to popular myth, there is no such thing as a free lunch.