Ironically we have been discussing this issue as well.
We are using 2.2.6 moving to 2.3 shortly.
As it appears to work now, when students post to a forum, the post can be seen immediately by others in the course. During the editing period, the post can be updated by the author. It can also be deleted by the author provided no replies to it have been made.
We would like to see and option for all forum types that would delay a post from becoming available/seen in the forum by anyone but the author and teacher, until the editing time has elapsed.
Our main concern is with inapropriate behaviour. This would provide some element of protection from students posting improper comments.
I had planned to open a feature request for this but since this will be done by someone else, we will monitor the request and vote on it.
Thanks to Marcus for opening the conversation on this important point.