Only a concept but interesting:
http://www.gizmag.com/touch-screen-s...eyboard/14181/

Maybe this is more up your street?
http://liliputing.com/2011/05/asus-u...let-combo.html
http://www.phonearena.com/news/Asus-...nboard_id24347

If they could do the same with the Transformer Prime so you could have a keyboard too...