Hitting several sites today is a new Fetz lab study where cortical recordings were used to directly drive paralyzed muscles in a monkey. More coming on the story later, but this will be one of those classic papers in the field.
Mentioned here, here, here, here, here, and here.
As a side note, we did something similar when I was working with Phil Kennedy. We hooked up a surface electrode to a patient's arm and used to the recorded signals to drive the stimulator. It was a very brief proof of concept type experiment, but worth noting in light of this study.