Room-temperature superconductivity looks like it might be a step closer to becoming a reality. Let’s stick with fiction for the moment though, what technology would you put in a cyberpunk world that makes use of zero-resistance electronics without the need for massive cooling? Super-fast computers? Super-powerful magnets? Maglev? Railguns?
Depends on what the material is like. If it’s brittle like ceramic (as some of currently highest-temperature superconductors are), there is not much you can do with it. But a metal that you can create wires and coils from would be revolutionary. Still, there are limitations to how much current density the superconductor can handle at a given temperature before quenching. Also, high-frequency logic circuits lose power to capacitances and inductances, not just resistances.
I am guessing it will be only really used for power delivery and electromagnetic applications.