Yes. MediaManager is still being actively updated. Currently I'm working on updates to the database backend so that it should be easy to "plug" in different database types as required. While doing this, the following features are also being worked on and targetted for release 1.0:
1. Multilevel categories.
2. File-Meta data (additional file information)
3. Plugins (perhaps in v1.5)
4. File previews
and of course,
5. Implementing and fixing issues in the current beta.... read more
The first beta release of MediaManager using the SQLite3 backend is now available. Also check out the screenies.