If no Higgs is found, it means our theories are spectacularly wrong, and that there are undreamt-of vistas of physics waiting to be explored.
No, it simply means that no Higgs was found. Perhaps that is because it doesn't exist. Perhaps it is because the $15B tool didn't work as anticipated. Either way, you can't prove a negative.
I stand by my statement. According to the theory, the Higgs particle spectrum should not only be observable by the LHC, but should be obvious. As for the LHC not working, either it's colliding protons, or it isn't. If it isn't colliding protons, or the detectors aren't reconstructing the collisions, nobody will draw any physics conclusions from that. The machine might fail in many ways, sure, but there's no way for the machine to fail such that the only symptom would be that the Higgs particle is missing.
If the LHC is colliding protons at the specified (and easily measured) energy, either the Higgs particles are evident, or they're not. If they're not evident, it means that either they don't exist, or they're much rarer than thought, or they're hidden in the data somehow, but in any of these cases, the theory is still wrong.
The LHC is as close to guaranteed discovery as science gets.
I know that it fulfills the practical purposes, and eliminates a massive range of other possibilities, but I find it irksome when anyone claims they can prove something doesn't happen or isn't there. The best that can ever be done is to prove that you did not observe it or it did not happen as anticipated.
Personally, I think the failure to take into account the effect of the ether on the phlogiston is going to skew the results. ;^)