Mind-Reading? For Real?

Elon Musk believes one of his projects is going to succeed in doing just that, translating brain wave patterns into speech. That isn't all we want from a direct neural interface between us and our cybernetics, but it's a start. Can his researchers pull it off? How would it work? Who'd get the first shot at this? Would it be voluntary? Meaning who gets to read your mind, and under what circumstances?