I was under the assumption though that only one spec for jedi knight/sith warrior out of the 5 was the tank (4 dps and 1 tank), and the the same goes for jedi counselor/sith inquisitor (3 dps specs, 1 healer and 1 tank). The same goes for the other 2 classes and their specs (one has 1 tank spec, the other has 1 healer spec).
It seemed at least from looking, that both healers and tanks are even.
But tbh, I can't see how people would rather stand back and heal instead of shoot force lightning/throw boulders at people and jump in crushing people as jedi/sith.
Hopefully things will even out though, will see.
You're counting specs, and not actual numbers of players in each role. As Blizzard keeps discovering, even if you offer players the choice to go for a less-played role within their class, you can't force them to choose it. Someone who is an avid DPSer will only DPS, even if they could theoretically respec into tanking/healing.