I spent a few minutes trying out the new support for using the Facebook chat with Jabber/XMPP, which is a great idea, since I hate to chat using the web interface. Sadly, it doesn't support grouping your contacts (you set a group, but it doesn't keep registered, probably they didn't implement that feature), and that make my empathy client look quite untidy...
I'll keep my account setup for a while, but I guess it will not be long until I remove it and continue not chatting with Facebook. Maybe some day they can properly implement the protocol...
Update: As Tobias Wich and Clifford Hansen had kindly pointed out to me, you can actually group your contacts, but only from the web interface. I've tried it and it works, but it's not really comfortable.