Mitigating physical and/or brain injuries is an obvious early application for this, and probably one of the easier problems to tackle with it. But if it turns out that eventually it really can facilitate two way communications between a brain and computer, such that the brain can understand the computer information along with the other way around... the possibilities and implications (good and bad) are enormous. Especially with A.I. added into the mix.
Along with the benefit of increased capabilities will come the increased risk from hackers and prying governments/corporations, etc.
Via technology, you'll effectively have telepathy available to you. There are tons of civilian and military applications for that.
Imagine if a psychiatrist could link up with a willing patient's mind and actually perceive their thoughts...
There would be a serious need for some governance on what is ethically/legally/morally allowed. Of course, in a world of billions of people, how many will ignore the "rules"?