It would be most likely (and only natural) that the Padjal are going to be playable. After all, body-wise they're Hyurs, so it wouldnt take a lot, or -any- coding to have armor fit on them and such.

"We gave your Hyur horns! You're now an entirely diffirent race to play! Rejoice!"

Personally looking through Limsa, there are a lot of (friendly) Mamool Ja travelers and merchants there for no apparent reason. Qiqirn and Goblins too. While it would be an absolute PAIN to code armor for Mamool Ja, Qiqirn and Goblins, basicly having to redo EVERYTHING, i'd love to play as either three of them. But since they have no allegiance to any group, it would be very unlikely.

But the thing that would interest me the most are mixed races. You cant possibly make me believe that over the thousands of years the lands of Eorzea and the people that came there are old, there wasnt any inter-species things going on. I mean, just look around in town with actual players. Elezen x Miqo'te couples, Roegadyns and Lalafell couples... We could have a lot of fun having mixed races.