Well, it depends on what character they want as their dark iron doesn't it?
For example, I've got a 120 night elf brewmaster that I'm very happy with race wise, but at the same time I'm race changing my shaman that's currently 113 to dark iron as soon as I finish the quests necessary when I get home tonight, simply because I want a dark iron shaman and not a dark iron monk (assuming they can be monks anyway, didn't check :P)