In Cataclysm many of the races will gain help from their brethren. The Night Elven Mages will be Shen'Dralar, and the Dark Iron dwarfs allies up with Ironforge dwarves.
Many of Azeroths races will have to face either doom or joining other tribes.
This is a great opportunity for Blizzard to make more money and gain more and happier players.
All the races will be able to choose from different skins at the character creation screen, they will share starting zones but have different background stories.
(Blizzard will of course give us the opportunity to change skins for the same price as race change)
Proposed skin varieties:
Alliance:
Night Elves - Shen'Dralar
Humans - Fat Humans, High Elves
Dwarves - Dark Iron Dwarves, Wildhammer Dwarves
Gnomes - Leper Gnomes
Draenei - Telaar Draenei, Broken Ones, Lost Ones
Worgen - Stay tuned
Horde:
Orc - Mag'har, Blackrock Orcs
Tauren - Taunka
Troll - Revantusk Trolls, Shatterspear Trolls
Undead - Forsaken Dwarves, Forsaken Elves, Forsaken Gnomes
Blood Elves - Cleansed Sunwell Elves
Goblin - Stay tuned
Inputs, anyone?
And keep in mind that many of these options ain't the best fit, comment more on the idea of skin/model changing than these ones.
Edit: Added some of your suggestions.
Also, should class restrictions apply?