Desktop accelerators
Building Colossae like the LHC does limit the pace of high-energy physics, but most of the theorising tries to tie in to what can be observed today - in stellar collisions, cosmic-rays etc etc. A lot of constraints on Large Extra Dimensions, for example, have come from astrophysical observations, especially the behaviour of supernova.
Wakefield accelerators will hopefully allow more compact accelerators to be built but there's a certain size limit downwards on the size of detectors and shielding due to the radiation produced by collisions. Hopefully they won't get too cheap or else someone will be making antimatter with them for something other than research...