My thoughts are that maybe next time around we will get a new healer/tank and maybe a new race. I personally am very happy with our current race choices as they are also very balanced.

Roe: tall, bulky, strong
Elezen: tall and lithe
Hyur: average humanoid
Lala: small and cute
Au ra: average height but scaled and tailed
Miqote: average height but ears and tail

I'm honestly not sure what other race could be added to make this more balanced than it already is (opinions welcomed). Viera seems to be on the mouths of many but we already have an "eared" race and two very tall races.

While I think everyone is entitled to their opinion I can't believe people are already saying that they are dissapointed with Stormblood. I can't wait for the expansion!!