(Though it sure would be nice if we had that bidirectional gateway working. It never seems to stay up.)
I tried to bring it up before, but anyways: drupal looks like a good way too go. It's fast, foss, flexible and with these modules http://drupal.org/project/mailman_manager http://drupal.org/project/user_mailman_register http://drupal.org/project/mailhandler http://drupal.org/project/listhandler and a bit of work it will be a perfectly synchronized mailing list - forum hybrid thing mirroring f.e. wine-user in a forum and vice versa. However, these modules have not yet been ported to Drupal 6 yet, also this all still looks a bit hackish. At the moment I have to do some intensive studying for an exam in three weeks, after that I'll try messing with those as I want to use them on my own website, too. When I'm ready with that, I'll report back. Don't hold your breath, it'll take at least another month... regards marcel