According to Roger Shawyer, his analysis is based on existing physics - Newtonian and relativistic. It is mathematically proven within both Newtonian and relativistic physics that momentum is conserved. His device, as proposed, does not preserve momentum. It is the moral equivalent of proposing that a properly shaped barrel could propel itself by the energy of ping-pong balls bouncing around inside it, to borrow an analogy. That he uses photons makes no difference - momentum is conserved, and his drive impossible. (John Costella says the same thing in this PDF (http://www.assassinationscience.com/johncostella/shawyerfraud.pdf), linked in the Wired article.)

If the Chinese manage to put a payload into orbit using this contraption - well, I won't be the only one eating crow. But as far as the science is concerned, the EmDrive is just as untenable as that water-powered car from last June (http://packbat.livejournal.com/159175.html). The only news here is that a professor at a Chinese state-sponsored university managed to fall for it.