The thing is that c as the 'cosmic speed limit' (which is different from "the speed of light" or "the speed that light travels") is something that 'pops' out of some very basic equations on electro-magnetism, Maxwell's equations.

Much of modern physics, including all of Special and General Relativity are fundamentally based on Maxwell's equations. The physics of the past century tweaks and probes into Maxwell's equations in minute and diverse ways, and in doing so, wondrous discoveries have been made. Super-luminal speeds simply break these equations in a fundamental way.

While nobody suggests our knowledge is complete, the physics of the past century or so has been so incredibly well tested, so much of modern technology relies on it working exactly the way we predict.

It is very hard to comprehend how Maxwell's equations can withstand such rigorous investigation, poking, prodding, manipulation, and reveal such unexpected realities of the physical universe, while at the same time being fundamentally broken with regards to c.

The physicists running the OPERA experiment understand this, and they themselves are incredibly skeptical of FTL neutrinos. This is why they've asked for help in trying to find any error in their experiment.

Smart money is on sub-light neutrinos, but everybody would absolutely love to lose that bet.

I wrote more about it here if interested:

Point-Five Past Lightspeed | is this your homework?
http://www.isthisyourhomework.com/point-five-past-lightspeed/