From the short video you can see that the monkey has a fine degree of control. We'll probably see the first human cyborgs in our lifetime , and that is a fascinating but scary thought. One of my favorite scifi novels was Neuromancer & will all these robotic extensions probably having some kind of computer chip inside - the concept of "direct brain hacking" may not be so far fetched after all.

http://arstechnica.com/news.ars/post/20080528-cybermonkeys-robotic-arms-bode-...

article excerpt :

Cybermonkeys' robotic arms bode well for artificial limbs

By Jonathan M. Gitlin | Published: May 28, 2008 - 12:00PM CT

Three years ago, we carried a brief report about a group of researchers in Pittsburgh who were working on a robotic arm that was being neurally controlled by a monkey. That work is published today in Nature, and it has been worth the wait.  I'll leave the comedy potential of cybermonkeys until the end and go into a bit of the science first.

The neural control of movement has many components, but the motor cortex is central to them. The motor cortex has several areas, but the primary motor cortex, a strip of brain just behind the frontal lobe, is where you decide to send out signals to peripheral nerves to tell your arms or legs to do something. The cortex is also organized somatotopically: the region that controls the feet is next to that which controls the leg, then trunk, arm, and so on. The practical upshot of this is that we have a good idea which region of the primary motor cortex needs to be measured in order to work on controlling a cybernetic arm or hand.