What hasn’t happened? live video streaming and two way audio, over commercial cellular networks, using commodity hardware?

I have been doing that with my phone for a few years.

Also, look at the part of the glasses behind the ear, now look at any recent smartphone teardown and see how they compare in size.

I’m sure Project Glass will eventually be interesting, this demo was really cool, but hardly a technological achievement. You can do the same thing by strapping a phone to your helmet.