In two minds here. I love the fact that someone has carried the idea through to reality, but wonder about the real range of applications. Basically my view is; if you like it, why not. Had I far more spare cash than I do, I'd probably set one up just to see the effect.
One practical use would be in the teaching of touch typing on manual machines, rigged to a computer program designed to teach it. Any one following through on this a making a fortune might remember where the iddea came from! - just kidding.
I believe I've seen 'Steampunk' keyboards so rigged.