Personally, I'd love a playable photonic officer. They could have the photonic shockwave as a racial trait on the ground

How about some delta quadrant races too? Talaxian, vidian, kazon, ocampa, krenim, malon, trabe, voth, vaudwaar, etc would all be very neat options.

I would also add hirogen to the list, but I expect with the eventual introduction of romulan playable faction, we'll get the chance to be hirogen without a c store purchase.

Back to the traditional star trek neighborhood, I wouldn't mind the option for Aenar players, they could be similar to andorians, but with telepathic traits.

Denobulans would be nice also. The artwork the the race already exists in the alien creator!

I would like to see a Federation Cardassian Officer (figure if there are Fed Klingons)
Federation Romulan Officer (some Romulan colonies are Fed Frendly)
And what I think would be the COOLEST a Federation Horta. Remember the Horta? TOS "Devil in the Dark"?