On Practical Ethics I blog about the ethics of attempts to genetically select sexual preferences.
Basically, it can only tilt probabilities and people develop preferences in individual and complex ways. I am not convinced selection is inherently bad, but it can embody bad societal norms. However, those norms are better dealt with on a societal/cultural level than by trying to regulate technology. This essay is very much a tie-in with our brave new love paper.