Basically an Omeka 2.0-compatible re-implementation of Omeka 1.x entities-related models and functionality. The main difference is that instead of users having entity_id's, entities now have user_id's.
This will eventually return all of the audit trail functionality and full name support present in Omeka 1.x as well as additional features (most of which are made to support the Crowd-Ed plugin), including the ability to 'favorite' items and provide community editing statistics.