Its discovery would double the spectrum of elementary particles in a way that is not obvious, that was was qualitatively predicted for decades, and that some people still find unbelievable. It could be interpreted as a discovery of new, anticommuting dimensions of space. The discovery of supersymmetry would surely be considered as one of the most amazing discoveries of experimental science of all time.

It sounds fantastic. It sounds too good to be true.

Nevertheless, some of us are now predicting that the LHC is more likely to see SUSY than not. A figure "60%" has recently become popular as a description of our confidence that SUSY will be there. Of course, if you evaluate many arguments, it is extremely unlikely that you end up with a posterior probability that is so close to 50%. So what many of us actually expect may be a number close to 90% or higher. We just want to be modest and cautious so we artificially reduce the estimate to 60%. We mix our qualified opinions with the sociological priors. ;-)