I don't want to be misconstrued a "bad HN commenter", so I'll say first of all, technically amazing. Also, UX is consistent and aesthetically pleasing (though admittedly incomplete; lots of actions are unexplained... e.g. what's the difference between Focus and Shift).

Technical and design accolades aside, IMHO I would not call this an improvement on existing discussion forums. In Part 4 of his post "Building a Better Online Community", he implies that a major problem is the signal to noise ratio. This web app has not solved that problem.

The extremely low barrier to participation, while inline with privacy ethics and democratic ethics, unfortunately removes important incentives to creating quality content. It is however, successful at enhancing anonymity and removing the (burdensome?) requirement of identifying oneself.

Let's take a step back and re-assess what we're looking at. It's not an improved discussion forum, it's an improved chatroom app, plain and simple. And for that, I credit it with certain innovation.