I must admit I have never been very keen on any of the Traveller aliens, they are all fairly unimaginative.
As for new books I would love to see in V2 format:
Soldier Book (Army/Merc/Marine Units, Large Battle System as background for characters to play a personal game inside/Ship Boarding rules/Miniature Combat rules/Combat Vehicles and Equipment)
Robotics/Cybernetics (robot types, when robots turn bad, robot creation rules, cybernetic surgery)
Alien Worlds book (detailed flora and fauna creation, planet building ideas/tables, encounter rules/tables, sample animal/flora/events to choose from, starport creation, detailed trading rules/planetside activities, rules about finance/banks, typical planetside organisations and places to visit etc, planetary law and administration, etc etc)