oh and i forgot the benefits there already are. the LHC was fitted into the same tunnel as the old CERN collider LEP was. But it is supposed to generate much more energy. For that you either need a bigger thorus (it's 27km in circumference) or better magnets. to get those better magnets they put a huge effort into research and came up with new manufacturing-techniques, new basic layoutprinciples and so on, together with a lot of other stuff.
It's as with some new nasa spaceship, many of the technologies used will eventually end up as cheap ass telemarketing products to make your car shiny
