Having a chat channel wouldn't scale ultimately, but I wouldn't mind chatting about tangentially related subjects to the questions. Does anyone else have interest in setting up and Irc channel. I have no idea how to do it, but found the #haskell channel very informative, and definitely has help create a sense of community.
I've gone ahead and registered the #mathexchange channel over on Freenode (irc.freenode.net).
It's set up and ready to go... I'll probably be idling there while things get going. Feel free to start using it whenever! Only suggestion is that people use their StackExchange usernames as nicknames.
For info, chat.stackexchange is now open; please feel free to drop by - see the "chat" link at the top of all pages on the main Q&A site.