I've been playing with gphoto recently. Started needed patches for proper menu sensitivities. Working on a revamp of UI - I'm thinking go with a film metaphor. Previews will be on a rolls of film. You can have sets of negatives, have a 'darkroom', cut and splice, rolls, etc.
Of course with the added benefits of a computer - you can add names to your negatives so searching is easier, annotate photos, reorder/rearrange till your heart's content.
Really I've got a slew of things I'd like to implement. Getting my mind around the whole of the problem so I can have a clear focus is the goal of the day. This has included a few mockups - glade is nice.