Another step toward Gattaca

NPR had a story yesterday about the growing practice of PGD, preimplantaion genetic diagnosis. That is, screening potential embryos before implantation, for disease. The story covers the controversy fairly well, especially the ethical thicket of thorns this practice raises.
Have you ever seen the movie Gattaca? In that movie, techniques like PGD have become so prevalent that those born without its benefit are a new underclass–not on race or gender, but on genetics.