There are two ways I can see this going.
1. The "ACS-IM-bot" acts as a one to many repeater much like a e-mail list server. A middle-man passing messages along, and archiving at the same time. The one issue I can think of is figuring out what topic someone was replying to. I suppose this could be solved by creating a "bot" for each topic.
2. The "ACS-IM-bot" actually creates a chatroom, and invites everyone on the list to join it. It would be present in the room to archive the chat. This model presents a few issues. Chatrooms are seperate from the normal IM app and must be joined. The creation of a chatroom would need to be keyed off of some consensus event. (when do you ring the church bell?)
As I type this I can imagine a hybrid... A live chatroom that could be monitored in list-server form by those not in the room, and replies "channeled" by the bot.
Perhaps "X messages" passing through the list in "Y time" could be what triggers a chatroom's creation and the ringing of the bell.
turning off IM-notifications on a topic via IM would be pretty useful as well.
