This scares the hell out of me. The idea of "overclocking" our brains by electrical stimulation is very new and we have no idea of the long-term effects of this. People who are desperate for an edge are the likely market and I suspect they'll be less likely to consider the risks.
Are there side-effects? Is there a small percentage of the population who will react badly? Are there long-term effects? I don't believe we yet know the answer to any of these things.
I'm all for the advance of technology, but this seems wrong.