Has anyone mentioned "Beggars in Spain," by Nancy Kress? It's a reasonably plausable fictional projection of what may happen as a small sub-group of humanity begins to "transcend" normal human constraints, while most people are (at least initially) left behind. The clever bit is the initial designer-genotype advantage is nothing more dramatic than freedom from the need for sleep. In less than a generation, those extra 8 hours per day give the "sleepless" almost complete domination of most sciences and intellectual disciplines, of course inviting resentment from the bulk of humanity.
Does anyone doubt that the first "post-humans" will be a small group of wealthy, technologically-savvy people, which will stimulate resentment and political attacks thinly rationalized as some manufactured danger?
</color>| "Thou canst not stir a flower
firstname.lastname@example.org | Without troubling a star."
| -- Francis Thompson