Goblins won't be a playable race.
They would need to replace the current Goblins with another neutral race.
Goblins are a neutral race in World of Warcraft, they "run" trading companies, and Booty Bay.
Blizzard would need to replace them.
Off topic a little, not sure if it was just rumours or something thats going to happen. But with the feature being able to switch sides, shouldnt there also be a feature to change race?
and why should the allys get worgans ?!?!