Unfeasible for 2-handed typing, but otherwise a nice idea. The only other immediate problem would be radiation. Are they going to put a thin layer of lead at the bottom to shield your wrist from radiation?
Also:
Computers - one small leap from typewriters
Laptops - one small leap from computers
Smartphones - one small leap from laptops
Smartwatches - one small leap from smartphones
Microchip imbedded in your skin - one small leap from smartwatches
Do not like where this is going. I'd sooner embed a bullet into my skin than a microchip. We aren't animals.