(I wish that statement were true tho...why can't we just be an 'American' race?)
I had many people refuse to give a race and told me to put "American."
Pretty much every last one of them was black.
I guess I'm not as fatalistic as you are. Certainly the concepts will continue to hold on among some. But I don't think we have to assume that even as soon as a generation from now the majority of Americans will think in terms of racial identity. And a big part of the equation will be the public/community role played by the children of interracial relationships.