I don't think Goblin and Worgen are necessarily the new races in Cataclysm. There were a bunch of other masks in the game files including Murlocs, Ogres, Naga, Vrykul, and something I think is a tiki mask.
I read on wow.com that they supposedly had other sources that Worgen and Goblins are the new races, but I just wanted to point out that those aren't the only new masks in the game files.