This combines group management with workflow and publishing chains.
1. Allow assignment of individuals to groups
2. Group definition is abstract and members can be added individually or by automatic association with a category, tag, page, role, etc. (or any criteria available in the User Management interface)
3. Producers create and submit content for review
4. Editors oversee one or more groups (editors only see content created by producers in their assigned groups)
5. Editors are notified when content is ready for review in the admin interface and via email
6. Editors can edit directly and/or make notes which get saved with the content
7. Editors publish or send the content back to the producer for more work
8. When the producer opens the content for editing again, the notes from the editor are there; the content producer can also make notes and send back to the editor.
And of course, you should be allowed to define a longer publishing chain if you need it. E.g. Writer -> Proofreader -> Designer -> Assistant Editor -> Editor -> Published