Thanks, but I just don't want to get into maintaining an account at all. I have concerns about how labyrinthine the security settings are, and the fact that they're not "set it and forget it" because Facebook periodically changes how they work without warning, potentially exposing parts of your profile until you catch up with the changes and re-tweak the numerous security settings. (That was true the last time I checked---maybe they've changed this?)
If the chat were on ChristmasChatter.com, it would be open to any registered MMC members ... cheesy ChristmasChatter is a greatly underused asset here at MMC. I've thoroughly enjoyed the chats that used to take place there, and I'd like to see more of them, but the rooms are usually empty.
I'd be more likely to maintain an account if I had family to keep up with, but my immediate family is all gone, and my aunts and uncle who are left don't use computers. It would be a great tool for keeping far-flung family members "in the loop."