I've been working on a similar concept but based on IRC.
Once authenticated with your Twitter account you can join a room using the URL, the path represents a channel. As I said, it's based on IRC which means that you can also join the same room using an IRC client.
The code is here: https://github.com/malditogeek/lalo
Show HN: An experiment - IRC channel from just a URL
lalo-g7stltno.dotcloud.com