I don't think my list has changed (though, the generic monsters in AA2 took away half my reason for wanting a beastiary and dropped it down on my list)...
1. Veskarium/Near Space source book a la Pact Worlds
2. Magic of the Pact Words source book with new spells, feats, magic items, archetypes, and class features a la armory but specifically related to magic/magitech.
3. Azlanti Star Empire/Vast source book a la Pact Worlds.
4. 'Advanced Players Guide' with new classes, class features, archetypes, feats, generic themes.
5. Ships of the Galaxy source book with new ships, ship parts, expanded starship combat rules, class features, feats, starship monsters, et al a la armory but specifically related to starships.
6. A full 300+ page bestiary with all the PF iconic monsters and new aliens (but no PC races).