I agree, misch. I think it's absolutely ridiculous that US citizens (or Australians, Canadians, New Zealanders, etc.) would have to prove their ability to speak English. A crucial part of the naturalization process involves the ability to speak and understand basic English, so even those who gained their citizenship by naturalization should still have a grasp of the language.
Still, if it's made a requirement, we'll have to put up with it, I suppose. At least it's one we won't have to worry about passing!