Scientists in the US have announced a technology that connects the brain to muscles via an electronic gadget. In temporarily paralyzed monkeys, the gadget enabled contraction of arm muscles. The hope is that eventually a similar device would allow para- and quadri-plegic patients to use the limbs they had lost control of. Of course, that sort of treatment is a long-way off, and even further off is signal transmission in the other direction - from the limb to the brain, which is tremendously more complicated. But it's exciting news, isn't it?
The thing with biotechnology is, all progress that is exciting, and especially progress that points to treatment for conditions formerly deemed untreatable, also takes us closer to a hybridization of humanity and technology that most of us find repulsive on an intuitive level.
For example, suppose we had the technology to eliminate a disease such as sudden infant death syndrome (which is basically what the name suggests... apparently healthy babies, usually in their first year, suddenly die), or any other disease you'd hate to bare a child with. One way that might work is to examine the genetics present in several of the mother's eggs, choose one that is free of the gene responsible for the disease, then fertilize and implant that egg. If that technology were developed, we could effectively eliminate any hereditary condition in a generation. Putting aside the question of value in "disease" (have you hung out with a child with Down Syndrome recently?), the same technology opens the door to selecting for any other trait parents might want or not want. In China, where parents are allowed to have only one child, there are currently 1.11 boys born for every girl, probably as the result of selective abortion. It gets pretty freaky pretty fast from there.
Similarly with this technology... in this proof-of-concept study, the monkey's brain was connected to the electronics, which was connected to their arm. What would prevent researchers from connecting one monkey's brain to another monkey's arm? What if we went strait from a computer to the arm? As the technology gets to the point of providing feedback to the brain (which would probably be necessary for any sort of fine motor movement), well, you can use your imagination.
Such is the paradox of technology. The further we develop, seemingly always with the best intentions (ok, sometimes just with the intention of profit), the further we remove ourselves from our humanity.