Some great comments and insight, Aurelie, and you've triggered a couple new trains of thought for me on the issue.
I agree that augmentation is not unnatural or repulsive, and also agree that a vocal minority will nevertheless view it as such. Anticipating the 'loss of humanity' argument I submit that 'humanity', as dissenters might mean it, is subjective, experiential and bound by perspective. It is neither good nor bad, and is simply a point on a continuum. We know it's parameters only through our own experience of cognition, affect and physiology. It would be arrogant to suggest that our experience of the human condition today is more pure, proper or correct than the human experience of a technologically augmented person at some point in the future. Indeed, in the long view it may one day be widely held that the human experience as we know it today, 'humanity', is unnecessarily limited by biology and therefore inferior. I feel you and I are much in agreement on this point.
I share your sadness that we may not live to see some of the more profound changes
It seems likely that the near future experience of being an augmented human will be as foreign to us today as our device-enhanced lives would be to Pythagoras or Aristotle.
A comment on your view of the likely motivators for augmentation (a utopian ideal being engineered through technology -- or even a noble desire to eliminate flaws). I certainly believe a strong segment of society will hold such ideals, but let me add a thought that occurred to me. Utopian goals require a certain degree of enlightenment, and I have doubts as to whether a greater percentage of future society will hold them than do those in society today. I expect very common motivators for augmentation will be vanity, the desire for power, jealousy, greed, entitlement and a perpetual state of dissatisfaction with the current body. Unless we can disentangle the primacy of self-interest from self-awareness (I doubt it can even be done), these tendencies will be prominent except in the case of great self-discipline. Too, unless human society overcomes its fixation on wealth and materialism (and consequently placing wealth-systems at the center of society and decision making), the manufacturing, marketing and sale of components will be highly commercialized. In this sense I agree with you that the tension between the small innovators and large establishment will be very interesting.
I wonder at the possible need for governments to expand their control over members of society when augmentation can increase the potential for an individual to inflict harm far beyond what it is today. In the year 700, a man with a sword could accomplish a certain amount of harm before he was killed; The force multiplier offered by a sword was limited. Today, a man with an automatic weapon or a bomb can multiply his force all the further by leveraging those tools. Even now we are moving towards a point where the distribution of technology and training is so broad that biological, radiological or nuclear weapons can be made in a home laboratory. What of the future man, with whatever potential to create harm afforded by future technology or body augmentation? Will an increase in human capability require a complimentary increase in human governance in order to maintain safety for the order of things? Will capabilities with the potential for great harm be restricted? Who will create these restrictions, and maintain the power to enforce them?
I have additional comments, but mostly ones of agreement and appreciating your particular insight on the issue. In the interest of being readable I'll end now and look forward to replies