From the last section of this webpage, it becomes clear that this technology may have a medical use. It is already starting to help paralysis patients and may eventually go much farther beyond that, to even creating robotic limbs for people missing arms or legs or personal robots for paralysis people.
As of now, however, the technology that we have is limited. Even though we have a method of mapping the brain and some knowledge of what certain parts of the brain do, we still have a long way to go. Though the method that we use for mapping neurons in ones brain does work, it is very inefficient. The method we use was barely able to map the neurons of the rats to bring them robotic arms, let alone mapping something as complex as the movement of an arm. We also know little about the human brain. We are only begining to learn what parts of it stimulate what actions, and that knowledge is necessary for most of the possibilities this technology presents to work.
The technology is not as hopeless as it seems, however. We will eventually overcome these obstacles and when we do, the medical world will be revolutionized. Even though there are things to help some of the causes, such as prosthetic limbs for paralysis patients, they have many problems, such as the fact that the body might reject the limb. The robotic limbs, however will not have these problems, since they aren't actually transplanted, rather attached.