[j_baker]

Well, actually that's true. From Man and His Symbols by Carl Jung (the guy who came up with the terms introvert and extravert):

"But if one is an introvert and the other is an extravert, their different and contradictory standpoints may clash right away... The extravert, for instance, will choose the majority view; the introvert will reject it simply because it's fashionable."

That doesn't sound like shyness at all to me. So yes, the original definition of introversion all along hasn't been shyness.