Disclaimer: I work in a similar lab (my adviser was advised by the senior author on the paper, who runs the lab) on a brain-machine interface project funded by DARPA.

What makes this awesome from a scientific point of view:

1) 2-dimensional decoders, where an individual controls a mouse with their mind, have existed for a while. What makes this really cool is that there are actually quite a few degrees of freedom in a robot arm, but they're basically using the same hardware. So the influence of software/algorithms in this case is pretty fundamental. There are a lot of papers on improved neural-decoding methods that at first glance appear really dry, boring, not the `sexy' kind of science with huge breakthroughs, but they end up being crucial to good performance as the complexity of the robot grows.

2) One participant was implanted with the electrode array 5 years before the study, and had the injury 10 years before that. Usually the signals don't last that long in monkey models. And we know that your cortex changes with disuse, so it's awesome that they were able to get usable signals so many years later.

What needs to get better are a couple things:

First, these decoders aren't perfect yet. What the Wired article didn't tell you is that the performance for the woman's implant was around 20-50% successful trials (still awesome from a comparison to no interaction)[1].

Second, incorporating sensory feedback is another challenge that is really hard to address, but also very important. Imagine building a robotic controller in which the only information you received about the robot's position was visual. That's the way this works. If we find a reasonable way to mimic sensors of muscle extension (a proxy for joint angle) then we can create more controllable devices.

[1] http://www.nature.com/news/mind-controlled-robot-arms-show-p...