I'd like to see the forum have the ability to "quote" someone when replying. The newest posts would always go at the top (unless you wanted to add a newest/oldest button that sorted the posts). The reason for this is that if, currently, one responds to a post within a forum thread, it literally gets buried within the sometimes extremely long thread. It goes underneath whatever post one responded to.
This mechanism isn't very helpful because the person you "quoted" or responded to may likely never notice that response, and it is difficult to tell who one is responding to currently.