Either much better superconductor performance at 78 K (instead of the more common 4 K) or much cheaper permanent magnets (the "Inductrack" configuration). Perma

Either much better superconductor performance at 78 K (instead of the more common 4 K) or much cheaper permanent magnets (the "Inductrack" configuration). Permanent magnet EDS has a risk problem: contamination of the magnet will incur an extremely expensive repair (the field cannot be deactivated), and putting together a vehicle containing lots of very strong permanent magnets is logistically challenging (to put it mildly!). AFAIK all existing maglev is superconducting EDS. The same issue limits the use of permanent magnet MRI. But new permanent magnets are a lot more foreseeable than new superconductors, since at least there are some candidate possibilities for magnets (Fe16N2 and L10-FeNi) while the plan for better superconductors currently relies on star charts and prayers. You could also come up with a way to make Litz wire without copper, but again that's very blue-sky and you'd have to make enough of it to build a whole railroad. The tl;dr is that according to physics, making stuff float is hard.