I was browsing TED talks the other day and found this.
http://www.ted.com/talks/todd_kuiken_a_prosthetic_arm_that_feels.html

It blew my mind. The technique they describe isn't all that complicated but the results are incredible. Where do you see the technology going over the next several years? I feel like having some sort of lightweight motor contracts like a muscle would propel this technology many steps forward.

That's extraordinary! It's too bad there's not a "good" way to just have wires act as nerves and extend down the arm as necessary. But it's great for those who can get to that type of technology.