It will tell us something about the fundamental particles of matter regardless of the outcome. For example, if they find the Higgs boson, it will confirm that theory and raise even deeper questions about physics which nobody can yet forsee. And if they don’t find it, then they’d have exchanged error for truth and have to go back to the drawing board with newer and better ideas, one of them having been falsified. The same goes for things like dark matter,dark energy, extra dimensions like suggested by string theory, and the possibility of a unified field theory.
Its findings will inspire future generations of physicists who will then find out even more about how the Universe works.
The same fear-mongering will create internet joke fodder.
Creationists will either try to claim that the findings prove God created the Universe or that the findings are all part of a “Big Science” conspiracy a la Ben Stein. Hilarity will ensue.
Time travelers might show up. But probably not.
It will give nerdy musicians more inspiration for their craft: