It WOULD be somewhat of a breakthrough if indeed Nordost came up with very thin hollow conductors.
Hollow conductors are NOT a new idea at all. I have some old Intermezzo E-M interconnects that uses hollow copper tube as conductor. Analysis Plus cables' main technology is the hollow cable also, even though they deviate from the ideal by making them oval (for flexibility) and by using stranded conductors. They do have some interesting thesis on why hollow is better:
The thing that would separate Nordost Odin is if each hollow conductor was extremely small, unlike the examples above, which basically use one big hollow conductor per signal leg.
STILL highway robbery, but I'm sure enough people with too much money will buy the Odin to make it profitable.