Relativity drive: The end of wings and wheels?

http://www.newscientist.com/channel/fundamentals/mg19125681.400
http://www.shelleys.demon.co.uk/fdec02em.htm

RESEARCHER:  <DIR>Detailed theory on how it works and experimental data:</DIR>
http://www.newscientist.com/data/images/ns/av/shawyertheory.pdf

BARDSQUILL:  what kinda drive is that?  Having trouble with pdf files
RESEARCHER:  In essence, the Emdrive is a resonating bottle full of microwaves. Because microwaves are a low frequency form of light, their behaviour is governed by Einstein's Theory of Special Relativity. And while microwaves and other forms of electromagnetic radiation may be thought of as very fast moving particles, they also have to be thought of as waves. At the same time that the constituent particles are moving at light speed, or their phase velocity, energy is transferred by the wave aspect travelling at group velocity. Group velocity is the result of waves of different wavelengths interacting with each other. While, according to Einstein, the phase velocity of electromagnetic waves is the speed of light in the appropriate medium whatever happens, and in whatever moving frame of reference the observer happens to be, group velocity varies. Group velocity can be any speed from stationary to light speed