Considering the LHC was built into the tunnels formerly occupied by the LEP (CERNs previous super-collider) I think it's quite probable that they'll just build a newer, better, upgraded version of it with more power into the exact same spot again (as they might be able to, considering the time to develop new materials and alloys and whatnot) - or use it as a pre-accelerator to an even bigger one, like they do with linear accelerators usually. So... they pretty much recycle most of their accelerators or at least the tunnels they dug for them.