Isn't this mainly an aesthetic thing, though? Consumer text-to-speech is certainly adequate for vocalizing almost any conversation. One could just use that to carry out "covert voice communication."
At the end of the YouTube video, he mentions being able to think "nearest bus" and having it query the internet and speak the results to you. This would allow you to augment reality without pulling out your phone, unlocking it, launching Google Maps, selecting your location, etc, etc. Sure, it sounds like the flying car dreams of the last century, but given they can recognize 150 words now, it hasa lot of future potential.
