..this reminds me of a Q&A I've seen were the audience asked about a 'butt slider' or at least some different butt options (bigger of course). Naoki Yoshida stood up and (jokingly) started to leave the stage. He didn't though and preceded to explain that every character add on would increase data going back and fourth from clients to servers, which would increase the volume of the data stream and perhaps cause slower game performance.
May be true but, other games have a ton of character options and they seem to stream just fine.
Although, it would be cool to see another race in game, I agree that time spent on the development of new races could be applied to existing character models. Don't get me wrong, our toons look awesome but.. some features/textures do appear a bit dated and, who wouldn't want some more choices when it comes to creating that perfect character...