Empire gets Trandoshans, Republic gets Wookiees, people can abuse the Legacy system if they want them for opposing factions. New planets to play through, new planet and class stories for Kashyyyk and Trandosha, happy players. What's so hard about this, devs? Give me my gun-wielding velociraptor already.
They wouldn't ever do wookies. Different animation rig, wouldn't fit gear, wouldn't work with current voice actors.
I think Transoshans are actually stretching it because of the voice/language thing, unless the devs maybe ran the existing voices through a modulator. I'd rather both sides get 'em too, because if the empire can get Cathar (which is pretty silly when you look at the lore) then I guess almost any race should just release for both sides.
EDIT: Actually, maybe, they could get wookies to work if they treat 'em like Death Knights in WoW, like, you START at level 50 on your starter planet, and require like lvl 30 legacy to be able to play one. Still though, with the dev team the small size it is, I doubt they'd use the resources for all new animations, etc...