Unfortunately this site doesn't seem to be running properly at the moment.
This concept is intriguing to me. I was pondering real-time updates to threads currently being viewed, and possibly other notifications to ease navigation. I've read a little about the likes of socket.io and am wondering if that's the route to take, but I have not looked deeper into the implementation at this stage of my project.
I personally would not have used Redis in lieu of a RDMS, even for a real-time site. I generally use Redis in addition to a database more suited for persistence. I would store data such as post content in the database and use Redis to keep track of when threads were bumped, which IPs posted recently. It's a lot slicker than database lookups in some cases. I've never really thought of Redis as a replacement for a real database but rather a supplement to one, but that's just me.
I've looked at Node.js and Express.js in the past. One of the reasons was that there can be a lot of duplication between server-side and client-side code when you're using different languages for each, so switching to an all-JS environment might alleviate that. Ultimately I went with tools I am familiar with.
Still, it's interesting to see people try new ideas.