Originally Posted by
choom
Round 2:
Dwarf - Frostborn Dwarf (customization option) and Ulduar Iron Dwarf customization for Dark Irons.
Night Elf - Children of the Forest (antler customization options)
Gnome - Ulduar Mechagnome (customization option for Mechagnomes)
Draenei - Krokul from Argus (customization option)
Orc - Half-Ogre / Mok'thanal (for example, Rexxar's new model)
Tauren - Taunka (major customization option, needs a whole new head)
Troll - Undead Ice Trolls (customization option, beefier frame with scary zombie features)
Goblin - Kelfin (customization option, could feature Murloc ideas)
Blood Elf - San'layn (based on Venthyr Kael, dead skin and red eyes, aka dark rangers)
Alliance Pandaren - Furbolg
Horde Pandaren - Tuskarr
Both of these could be relatively closely based on the existing Pandaren frame. Many of these are unintentionally centered around Northrend, so these options could all be features of a revamped Northrend expansion.
Between the covenant allied races, and the second round of added customization options, the neglected races get caught up and all the other playable races gets something new. I don't think any off these, and their faction alignments, would be a stretch in the lore. And seem pretty feasible if they decided to implement all this.