They're the descendants of Naga Sadow and Marka Ragnos don't cha know. Then there's the blind, force-seeing Miraluka. There's two more.
"Among the most exciting character types you’ll be able to choose from is the Sith Pureblood. For the first time ever in a video game, Players can choose to be a member of the original Sith Race, the red-skinned descendants of such notorious Sith Lords as Naga Sadow and Marka Ragnos," the official BioWare site for The Old Republic.
"A near-human species with unrivaled strength in the Force, Miraluka can become powerful Jedi Knights. Hailing from a homeworld with no visible light waves, the Miraluka evolved to see their surroundings entirely through the Force."
There's also the "green-skinned Mirialans" who make good Jedi Consulars tease BioWare. "Mirialans are known for their symbolic facial tattoos and natural agility. They are also respected for their patience and insight."
Last but not least are the Zabraks (Darth Maul from The Phantom Menace). "A proud species from an inhospitable world, Zabraks are among the few with the determination and ferocity to become Sith Inquisitors." More will be unveiled in time.
BioWare tell us the "list is not yet complete" for all the playable non-human species we can choose from. "We look forward to announcing further options in the coming months." Star Wars: The Old Republic releases exclusively for PC with no console plans.