From Lisa Grossman, (New Scientist, October 5, 2011), who says they’re “flooding in”:
Some knock the result. Nobel laureate Sheldon Glashow and colleagues point out that faster-than-light neutrinos ought to produce shock waves, which in turn would produce “virtual” particles that should rob the neutrinos of energy (arxiv.org/abs/1109.6562). If they were ever faster than light, they wouldn’t stay at that speed for long enough to account for OPERA’s results.
Others potential flaws are more prosaic: some papers try to pinpoint hidden sources of error, like a mis-synchronisation of the clocks at either end of the neutrino beam (arxiv.org/abs/1109.6160).
Still others explore ways in which the OPERA results line up, or conflict with earlier limits on neutrinos’ flight speeds, from supernova SN1987a, for example (arxiv.org/abs/1109.5682, arxiv.org/abs/1109.5917) and other detectors.
But the majority of papers hunt for ways that would allow the result to be right. As well as several proposing shortcuts through extra dimensions …
It hasn’t been a more fun time to be a theoretical physicist in a century, we’re betting.