As far as using websockets with Rails goes, I just wanted to mention that I've been having a really good experience using the websocket-rails gem (https://github.com/DanKnox/websocket-rails) in a text game (MUD) I'm working on as a Rails 3 app.
A Rails-powered MUD? You're doing God's work, son.
That sounds amazing! When you've got this MUD on Rails going, please do submit it here. Similarly, I'm working on a MCaaS (MUD Client as a Service ;]) half tongue-in-cheek to learn more about Node. There's no feeling like using new & exciting tech to solve the problems of our neckbearded forefathers.
That sounds cool too, have a demo up anywhere? I'm kinda doing a deploy as I code thing, I've added the url to my profile.