Let's put it this way then.
Normal quillboar:
- Have male and female models. They both look the same (except for boobs), they both have the exact same animations.
- Aren't made to wear armor.
- Don't have player emotes or spell animations.
Quillboar brutes:
- Only have male models. Their faces are void of any humanity, even more so than the current worgen male model.
- Aren't made to wear armor.
- Have the same emotes and animations as the tauren.
Let's compare this to the Vulpera, who:
- Have male and female models. They look as different from each other as male and female goblins do.
- Are made to wear armor.
- Have all the emotes and spell animations, based on the goblin skeleton, but upgraded to WoD standards.
And then let's see the other candidates:
Ogres:
- Don't have female models. They have virtually no different faces.
- Aren't made to wear armor.
- Have some emotes and spell animations, but nowhere near the WoD standard for a playable race.
Sethrak:
- Don't have female models. Their necks would be in the way of everything.
- Aren't made to wear armor.
- Don't have emotes or spell animations, other than a few ones shared with worgen, saurok and saberon.
Kul Tirans
- Have male and female models. The male ones seem loosely based on the vrykul model, the females are based on the human model.
- Are made to wear armor.
- Have some emotes and animations, not player-ready just yet.
Based on this, I'd say it's almost a guarantee Vulpera will be playable, Kul Tirans will probably be playable, but they need some work, Ogres, Sethrak and Quillboar will not be playable in the foreseeable future.