Another essay of mine On the way to Nanomedicine: Decisions and technology past and future is pubilshed in nanonewsnow In it I make the case that society already has widespread internal and external devices that enhance are capabilities both physical and mental. The cases that are made for the rejection of superior performance or finer grained modifications are inconsistent and harmful to individuals, individual rights and the productivity of society.
A recent conference the Human Enhancement Technologies and Human Rights conference presented by the Institute for Ethics and Emerging Technologies had discussions on many of the topics in the essay. Excellent coverage of the conference discussions is at the rational longevity blog.
Part 1 of coverage, Part 2 of coverage,
Part 3 of coverage, Part 4 of coverage,Part 5 of coverage.