The current User/Group/Role Preferences are tied to the Java Preferences API.
JS2-869 will provde a new, simplified and more efficient preferences model doing away with the Java Preferences.
For the User/Group/Role security principal elements this will require a drastic API change but also allow for better and improved integration with the backend systems.
The Portlet API USER_INFO attributes need to be mapped (filtered per portlet application) to the User attributes.
Furthermore, full backend integration needs to be provided so for instance LDAP can be used for storage/retrieval as well. This will require large enhancements to the LDAP api (which currently doesn't support mapping custom attributes yet).
Finally, the admin portlets need to be enhanced to provide retrieval and (optionally, if the backend supports/allows is) modification of attributes per User/Role/Group.