Moving extended conversations in comments into chat seems like a good idea. However, generally those types of chats are not real time. Additionally, users have to manually check the chat rooms to see if any new messages have been posted.
In order for chat rooms to have the same benefits of extended comment conversations (notifications), it would be ideal if a user could flag a chat room they are interested in. When a new message is posted to the flagged chat, the user would be notified in the standard manner with a red notification in the upper left. Perhaps this flagging could be automatic in the case of moving a comment conversation to chat.