@fulhamish: You're not reading my position carefully. For species *in general* (not just humans), intraspecies population boundaries aren't set in stone, and evolutionary divergence is not monotonic under conditions of varying reproductive isolation. It's not just humans who might be affected by developments in genetic engineering. And the fact that we *can* tentatively construct biological classifications of humans, as we do for other species, doesn't mean the way we *do* talk about race is solely/primarily derived from or dependent on those classifications. None of this is either fundamentally optimistic or fundamentally anthropocentric, except insofar as the way we talk about race is *already* anthropocentric--and failing to acknowledge existing anthropocentrism isn't logical, even if it's convenient for your argument.
@Peregrine Falcon: First, there absolutely are biological or technical issues that affect the ethics of human genetic manipulation. However, it was never my contention that all the ethical issues are contingent on biological/technical issues, and I absolutely agree that genetic manipulation will have both classist aspects and ethical issues of control over the offspring. Again, I simply don't think those concerns will stop it from happening. I mean, think about all the things we *already* do, and even take for granted, that (a) fundamentally alter our offspring's lives and (b) favor rich kids over poor kids. Gene manipulation is an especially direct expression of those ethical concerns, but it's hardly a unique one. Ethical concerns will influence the pace and direction of developments in gene manipulation, but that's not the same thing as stopping it.