In a more serious post from me...
1) More playable races (and not just Star Wars and the Amazing Technicolor Humans)
I'm talking Rodian, Wookie, Sullustan, Trandoshan, Mon Calamari, Duros, Nautolan, Droids, Jawa, Kaleesh, Kel Dor, Selonian, Gormak [especially Gormak])
2) More Space Battles and Space Battle-type variety.
New missions (not harder versions of the same missions), Multiplayer Co-op (either more than one ship or one ship and 1+ gunner), Multiplayer Vs (Even StarFox 64 had this and that's the closest system that this space combat gets to)
3) More Fluff
New toys, better/different animations, not penalized greatly by flavor items (like a 10 hr cooldown on a toy that lasts 3 seconds)