The main decision that needs to be made about this module is what types of lists should be offered. An announce-type list can be done entirely within Drupal and not require extra mailing list software. If we want full mailing lists where anyone can email to post then we need to look at full mailing list packages to make a Drupal frontend for.
Let the list know what you think sites will want and maybe move the debate over to the wiki or hackers list since this isn't strictly an implementation decision. -Neil
