I'd argue that this is worse than a normal keyboard. What it gains in versatility it loses in physical feedback.

Ever try to touch type on an iPad? Super tough.

It'd have to make a really, really slightly different noise for each key you press. That way you can tell what you're typing without looking at the screen or at the keyboard. Perhaps like a really soft, sped-up whisper of the sound of the letter.

Anyway, I'm sticking with this for a while; http://www.daskeyboard.com/blog/wp-content/uploads/2010/07/daskeyboard.jpg Superb tactile feedback... which is what I was hoping for when I saw something named "Tactus"; alas!