BuddyPress.org

would be good to have a plugin that would let you admin a message in case there’s news or updates to the message if you think its going to change that often.

I believe that was the original intention for the site notices in BP:

hxxp://mydomain.com/members/admin/messages/notices/

You can re-position the notices display with the following template tag:

<?php

if ( function_exists( 'bp_message_get_notices' ) )

bp_message_get_notices();

?>