Oh come on, just look at wacom tables. One of their smallest ones is almost $230 (
http://www.wacom.com/intuos/4x6.cfm) thats only 4x6 inches and what this looks like is at least 12x6.
So lets just use the 2.4 Ghz 15 inch as an example (as it'll probably use more processing power). So thats $2500 plus the costs of the extra hardware. Pretty soon you're looking at that $3300 price point.
Photoshop is already compatible with similar things like the wacom tablets. Tablets are awesome for photoshop and it probably wouldn't be hard at all to translate that potential to this... ...keyboard thing
I think that it'd be really cool to do something more like star trek, almost a cross between that OLED keyboard, this apple keyboard thing, and the iPhone. Also for people who want tactile sensation they could make it vibrate a little bit when you hit the keys, i know one of the LG phones does this with it's touch sensitive buttons.
So kind of make a big iPhone like keyboard, so that buttons can appear or disappear. It also would be cool for gaming because you could completely customize your control scheme rather rather than working around using the keyboard.