Okay you've heard a lot tension political intrigue and downright civil uprising occuring in both factions after the cataclysm, not to mention outright war, there is is something up with every race, and leaders etc. Should the factions break up, how would the races coalesce together again?
You are allowed any number of factions, they don't have to be of the same number of races either - remember that in-game some races are far more numerous than others. The new factions don't all have to be bound by race either, instead they could be bound by ideals like the Light , the shadow or the Spirits etc, which would throw some classes of any race into a faction. It could be combination of both. You decide.. these are the races you are allowed to choose from, and there can be independent faction. However there must be factions.
Races to choose from.
Human
Orc
Night Elf
Forsaken
High Elf
Ironforge Dwarf
Tauren
Taunka
Wildhammer Dwarf
Grimtotem Tauren
Blood Elf
Dark Iron Dwarf
Forsaken Elf/Darkfallen
Darkspear Jungle Troll
Raventusk Forest Troll
Winterfang Ice Troll
Draenei
Broken
Ogre
Furbolg
Nascene Naga
Bilgewater Goblin
Gilgoblin
Worgen
Vry'kul
Cenarion [sons & daughters/dryads&Keepers]
Steamwheedle Goblin
Ebon Blade
Dragonmaw Fel Orcs
Netherstorm Fel Elves
Concepts:
Light, Shadow, Earthmother, Spirits, Nature
You don't have to use all the races but give a brief reason for the faction composition.