Engine:

- Added MostPopularActor, LeastPopularActor, MostRecentActor and
LeastRecentActor as possible ReturnTypes for FindEvents and
FindEventsId (LP: #493903).
- Let {Find,Get,Insert}* hooks know the bus name of the caller, when
executed over D-Bus.
- Add an extension implementing a data-source registry (allowing to disable
data-sources from a centralized place and see their description).
- Overhauled FindRelatedUris for better results and improved performance.
- Changed FindEvents, FindEventIds and FindRelatedUris to not treat zeros in
the given TimeRange specially; "(0, 0)" can no longer be used (LP: #490242).
- Fixed a crash in the GtkRecentlyUsed data-source parsing malfored .desktop
files (LP: #526357), and added support for more file mimetypes (LP: #510761).
- Fixed a crash in the GtkRecentlyUsed data-source trying to read broken
symlinks disguised as .desktop files (LP: #523761).
- Fixed a crash in the GtkRecentlyUsed data-source which happened when there
was no display friendly version of a URI (LP: #531793).
- Renamed --no-passive-loggers option to --no-datahub. Output printed by
zeitgeist-datahub is no longer visible in zeitgeist-daemon's output.
- Added --log-level option to change the output verbosity.
- DeleteEvents now correctly removes any unreferenced values (URIs, actors,
etc.) and not only the events themselves (LP: #491646).
- Fixed insertion of events with a payload (LP: #557708).
- Fixed an exception in DeleteEvents.
- Fixed event deletions not always getting committed (LP: #566184).
- Ignore deletion requests for non-existant events.

Python API:
- Made the Interpretation and Manifestation classes iterable.
- Added symbol lookup by URI, in the form of dictionary access.
- Fixed the display name for Interpretation.SOURCECODE.
- Fixed find_events_for_values and find_event_ids_for_values (LP: #510804).
- Added a get_extension() method to ZeitgeistDBusInterface, to get convenient
access to D-Bus interfaces provided by engine extensions.

Overall:
- More fixes and code enhancements.
- Manpage updates.
- Translation updates.

Per maggiori dettagli ecco il post sul blog di Siegfried e l'annuncio ufficiale su launchpad. Da quel che ho potuto sperimentare non sono ancora state implementate la maggior parte di queste modifiche nell'ultimo Gnome activity jounrnal che comunque continua ad essere aggiornato con regolarità.