Airless tyres. Something that could be developed for bikes?

The tyres on that bike in the promo vid do not look good at all. They are well stiff, not deforming around the boulders at all.

That what I was thinking too, when I went MTBing, I have to stop a couple time to let some air out to get some grip (especially on those slippery tree roots), I can't imaging that being any better in the slightest.

Only advantage I can think of is a dutch bike, it's probably the last piece to the puzzle in making it maintenance free (and provided a lots less headaches to the mechanic to replace inner tube).