Are there any future plans to allow for easy integration with AD/LDAP? If you guys aren't planning on adding it yourselves, it would make it easier for someone else to add if you decoupled the username and ID fields (and the group name and ID fields). Beyond using a directory system, people (and departments) change their names and from looking at the schema it looks to be a maintenance headache to change someone's username since it's used as the primary key.
