The result is due to the wave nature of light, not because the speed
of light was actually violated by a photon.
http://www.msnbc.com/news/435007.asp has a pretty good writeup of
it. Here are some excerpts:
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"Our experiment is not at odds with Einstein's special
relativity," [Lijun Wang, Alexander Kuzmich and Arthur Dogariu] said
in a statement. "The experiment can be well explained using existing
physics theories that are consistent with relativity. In fact, the
experiment was designed based on calculations using existing physics
theories."
"We are in the middle of a battle to save Einstein's relativity
theory from bad press interpretations of our experiment," Dogariu
said in an e-mail message.
Another physicist familiar with the experiment, Aephraim Steinberg of
the University of Toronto, agreed that it was easy to misinterpret
what the NEC researchers had done.
"The researchers have been very careful in the point of view that
they've taken," he told MSNBC.com. "Certainly in these
experiments, there is something that's faster than light or even
a negative speed, which is very dramatic. But then we have to back up
and interpret what's going on."
"It's very different from what we might want in our science-fiction dreams,"
he said.