Kel Dor, Togruta, Quarren, Mon Calamari, Kiffar, hell, even Rodians and Bothans... With so many awesome species in the Star Wars universe, I can't understand why we don't have more variety.
Most of all these I'm surprised there are no Kel Dor or Kiffar, Master Gnost-Dural is possibly the second most celebrated character by TOR (following Revan, I'd say) and we can't even choose his race as playable characters? Kiffar would be incredibly easy to implement. They're practically human with unique facial tattoos and dreadlocks. They have a very popular character example (in Quinlan Vos) not to mention two characters from one of the TOR-timeline novels (Shigar Konshi and Larin Moxla from Fatal Alliance).
Simply put, we need more races.