Another suggestion. AOL's IM function now contains a live alert that the person you are talking to via IM is typing a reply. It lets you know that the conversation is ongoing.
It would be neat when a compose window opens on IHub to have the post to which is applies show a "A Reply is Being Composed" message. The "A Reply is Being Composed" would toggle on only so long as the compose window was open. When the compose window closed -- either by submitting a post or by simply closing it, the "A Reply is Being Composed" would also toggle off.