I would love one of these keyboards, but their layout isn't great, as well as the price.
For the time being, they're just concept designs in my eyes.
As OLED technology advances and becomes cheaper though, I can see these becoming a lot more accessible.
The most I could bring my self to spend on one of these would be £200 because I could get so much use out of it.
Once you can get a mainstream version, I'll be all over it.