Ethan Siegel at the StartsWithABang blog writes:
"Have you ever wondered why the masses of the fundamental particles have the small values that they do, compared to, say, the Planck scale? Whether the fundamental forces all unify at some high energy? And whether there's a natural, compelling particle candidate for dark matter? Well, in theory supersymmetry (or SUSY, for short) could have solve all three of these problems. In fact, if it solves the first one alone, there will be definitive experimental signatures for it at the Large Hadron Collider. Well, the LHC has completed its first run, and found nothing. What does this mean for theoretical physics, for SUSY in particular, and what are the implications for string theory? A very clear explanation is given here; it might be time to start hammering in those coffin nails."