This is a really neat idea, but it'll only be good if the actual keyboard is good. After all, a keyboard is first and foremost about typing, and if the keys aren't good (poor size/spacing, mushy, loud, poor travel, etc), then it's just a novelty. Also, I'm guessing there's no backlighting, which has become very common these days, so not having it has become even more of a non-starter for many than it was several years ago. And, of course, I'd love at least the option of a Trackpoint.
This also seems to provide a fairly limited and expensive solution. I'd imagine the vast majority of people are going to set it to be how the typical keyboard in their region is and then leave it that way. They could instead just buy a keyboard that already has that layout and save $100+. Clearly it has plenty of interest, though, and it'll be interesting to see what comes of it, not just with this keyboard but possibly with it leading to innovation in others.
Also, what happens when the battery dies? Does it reset and forget how the user customized it?