Warning: I don't know much about the CMS yet, so the following may be ramblings of an ignorant day-dreamer:
It would be nice to have some sort of UI that can be configured to read/edit db fields based on permissions - and provide a log or notification of changes. It should be general so it can apply to any custom db implementation --perhaps read the list of available tables, types etc? Okay, this is low-level CMS extended to end-users --think canned DB UI access, not a CMS for an online newspaper etc. Still, a basic UI using a db that tracks tables, fields, field-types, data-input-format-constraints/triggers, permissions etc. could be useful for many reasons --especially if configurable.
Other thoughts:
Perhaps a CMS could include remote accessibility from a client tcl/tk graphic UI accessing the db/file-tree remotely in addition to browser access ..to reduce computing burden on the primary, publishing server (for scalability)?
Would the tcl/tk provide more compatibility and consistency between platforms than depending on javascript/java applets et al for any dynamic editing processes?