He starts out his presentation by asking what the motivation of transhumanism should be. The answer, he says, should be medical treatment, adding that "the power to heal is the power to enhance." For example, all the advances in longevity we've had so far have come from medicine, he says. (I may have misheard his remark*, but that claim is almost certainly false — improvements in sanitation and nutrition have had at least as much as medicine to do with the lengthening lifespan. Still, his point is clear.)
Naam names various human limitations and defects that scientists are now trying to transcend, and says that incorporating these potential enhancements within the realm of medicine "is good for transhumanists in that correcting these deficits is considered medically legitimate." In other words, he wants to bypass the moral questions such research raises, instead protecting the research through P.R. and strategic positioning: who cares what it all means, how can we make sure the public lets us do it?
Naam is right, of course, that the line between therapy and enhancement is blurry; that is a point eloquently made by Leon Kass in his New Atlantis essay "Ageless Bodies, Happy Souls," and it was a major theme of the President's Council on Bioethics report Beyond Therapy. But we can certainly still recognize a distinction — indeed, Naam's presentation presupposes a difference between the two, otherwise he would have no reason to argue that we should hide enhancement within the realm of therapy.
Nothing much new in this talk, though that's probably not Naam's fault. The presenters are really rushing and aren't able to fit much into these crammed time slots.
*UPDATE: Naam tells me I did indeed mishear his point. I think I was attempting to summarize his point and did so poorly. Judge for yourself: the on-the-fly transcript is here, with the part in question beginning with the third paragraph.