well, as a product of a bi-racial relationship and currently in a bi-racial relationship, all i can say is... what the hell?
people who are in the KKK and Neo-Nazis are the ones who talk like that, and we see how great they turned out "sticking to their own kind"!!
being a member of more than one race makes you realize that you not only have one race to make you special, but two! or even more than that!
i get to be proud from being from Sweden AND Guatemala, now how many other people can say that???
and besides, originality comes from the inside, not from where your parents are from!
and as for losing your cultures identity... a culture doesn't lose their identity, they become part of a new one! African-Americans may not know as much about their culture as ones actually from Africa, but they still have their strength in spirit do they not? Hispanics may not remember much of their Aztec heritage, but don't they still have the warriors courage inside them? Caucasians may not have the same beliefs as when they were all English, but they still have that adventurous spirit!
Culture, beliefs, those kind of things don't "go away" once you go outside the race, but instead gives those many wonderful gifts onto their children! In turn, the children will combine everything from their ancestors and make something great! Say what you will about the US, but it's an example of all the good and hope people can do when they don't concentrate on race, and focus on the greater good!
^_^ at least that's what i think, anyways...