To report bugs or request features, see: http://bugs.shaftnet.org/.
The Photo Organizer web site is a wiki, allowing anyone with an account to make changes. Anyone with a bugtracker account has wiki permissions; just sign in with the same username/password.
Current development plans can be found at the Development Plans page. This page also lists changes not present in the -stable tree.
Photo Organizer's current development code is always available via git at:
git://git.shaftnet.org/po.git
And via gitweb at:
http://git.shaftnet.org/cgit/po.git/
The 'master' branch is where all development occurs. The 'stable' branch is where patches against the most stable branch land.
To subscribe to or view the mailing list archives, see: http://www.shaftnet.org/mailman/listinfo/po-devel
Subscribing to the Photo Organizer project page on Freshmeat.net will not only tell you about new releases, but will also help the developers gauge ongoing interest.