I don't tend to opine on matters scientific, so take the following with a hefty pinch of salt, but...
Some background: light travels at different speeds through different substances. The classic "186,000 miles a second" is the speed through a vacuum. But the speed of light through air and glass and water and diamond are all different: the difference between air and glass is why prisms and spectacles work; the difference between air and water is why an oar appears to bend at the surface of the water; the difference in speed between space and air is why the daylight sky is blue.
The experiment in question involves sending neutrinos
I could, of course, be wrong. Or worse, I could be unoriginal, but I'll back relativity over previous estimates of the speed of light through rock.
Update 2011-09-25: Corrected the distance involved.