So, it's similar to RetroShare?
I've never used RetroShare or anything similar, but from a quick look at Wikipedia, the difference seems to be that with WebRTC you don't have to install and manage any software. Having latest Google Chrome or Mozilla Firefox would be enough. So simplicity and usability must be a big plus for adoption,
not so sure about security though, but that can probably be worked upon.
Running on windows. Using browser plug-ins or javascript. What could go wrong?
Well, the video in the OP is called Linux Action Show, so it can definitely run on Linux too. Ubuntu and Mint come equipped with Firefox by default, so no prob there.
What is critical is how they keep the private key secure (if they even have one). As long as private key is hidden well enough it doesn't matter if it's javascript or something else that handles the rest of the protocol.
Maybe integration with Bitcoin hardware wallets might come in handy.