From a reader auditioning to be my physics guy. Nobody achieves Jonah’s-guyhood unilaterally:

Okay, as your “Physics Guy” (you probably didn’t realize you had a physics guy, but here I am, volunteering for job) I thought I’d throw in my two cents about your German physicists and their claim. I think (after scanning the paper) that they’re exploring a phenomenon to do with the optical properties of certain (very strange) kinds of matter. Basically, as your previous emailer pointed out, the important thing is that information can’t be transmitted faster than the speed of light, and this doesn’t happen here. Rather what’s happening is that the group velocity of light in question exceeds c – roughly speaking the peak of the wave travels faster than light but the information (essentially carried by the front of the wave) still travels at the speed of light. This, of course, leads to all kinds of weirdness, for example the peak of a pulse can overtake the front. This is discussed a little in the Wikipedia article on Faster Than Light and also in the following article: http://news.bbc.co.uk/1/hi/sci/tech/841690.stm
I should stress that I may be wrong about the particular phenomenon the paper you cited is talking about, but my best guess after a quick scan is that it’s something closely related to the above. If not, apologies in advance.