Compare the process of forming a Meetup group. There are basic
standards of behavior and usage -- applied via review after the fact,
soft-security style -- and measures of activity. But as soon as you
finish filling out a form describing your group, it has been created +
is visible online + has its events included in a global calendar, and
starts to get updates and support.
Wiki Borregos has been operating in this manner for some time. See
http://meta.wikimedia.org/wiki/Wiki_Borregos_CCM_Student_User_Group
We originally put our info as a student club, but when it became obvious that the program
to support such an organization had died, we put in to be a user group.