One drawback I just thought of with these... How many people adjust their tire pressures for different conditions, track days, autocross, etc.?? It would appear there is no way to adjust the "tension" on these, so that could make for a "less than enjoyable" ride for many of us.
As stated above, though, these things get posted every few months... I doubt they'll ever actually make production, except for some exotic vehicle.
My guess that they will have the sidewalls covered to look like conventional tires....If they did that I wonder if they could make them hold air so the pressure could be adjustable....