There's a tag users button at the top of the thread.
This stuff is interesting, but what's the point or it?
Some of us thought it would be a good idea to be able to mention a user in a thread so that they would automatically be notified. That way if you wanted someone's input, or just wanted to make them aware of something they might find interesting, you could do it right there in the thread without having to send a separate PM.
The extra tag feature at the top of the thread, and the notification of being quoted seems a bit excessive to me.
I'm not so sure we need the little counters under the user names/avatar either.