We often find that users want more than one individual to be able to edit a shared dashboard we can work around this by using shared accounts but that's not ideal. So why not put a Google Docs like approach to permissioning.
Public / Private Dashboards (We have this now in Omni)
Dashboard Roles (Admin, Contributer, Viewer etc)
I think publishing lists could improve perhaps move to a google groups model
A group has settings between invite only, open
That way a user can simply subscribe to the correct group and recieve the correct dashboards and reports