While watching Star Wars Rebels today, I just realized we never see aliens enlisted by the Empire. Never a wookie behind a control panel or General Ackbar in Stormgear dishing out commands. It's almost always an old caucasian male with stuffy British accent as a commander, when not behind a mask.
As for the rebels, there's Ackbar, the big eyed co-pilot of Lando in the Falcon in ROJ, Zeb, Chewbacca, diverse Jedi of multiple alien species, and so on... Yet not one non-human amongst the Empire troops (droids not included).
Which leads me to the question... Is the Empire nothing more than xenophobic space Nazis? Sure, they never mention alien genocide, and the closest thing to it was the deaths of supposed humanoids on Alderaan, but it's just something that strikes me as odd.
Anyone think we'll see some alien commanding officers in TFA, aside from Sith?