I was thinking of just a tiny informative/warning message line with the same contents you can see in the "Who's online" screen (so the info is available, as drl pointed out):
Quote:
Replying to Thread
 Congrats to RudiC - 3000 Thanks!
It's just to make it a bit more comfortable - everybody can have this info, but in another screen. And, it doesn't mean a new post is going to come in the next few minutes or at all; the replyer can quit any time without posting anything.
Thanks for your valuable idea using the "Topic Review" list for recent updates - I've seen that before but never thought of using it this way other than by coincidence.