Earth and Sky has an interview with National Medal of Science winner and Mallinckrodt Professor of Chemistry at Harvard University, George Whitesides.
Whitesides is regarded as one of nanotechnology’s pioneers, although there is no love lost between him and the Drexlerians, as evidenced by his views on nanobots, which are pretty much the same as most mainstream scientists:
“It’s a neat science fiction, and it’s a good thing to think about. After all, it is true that one has micron-scale things, called bacteria, which do undergo exponential growth. But the characteristics of bacteria, as an engineered thing, are so many orders of magnitude more sophisticated than anything that we can build right now, that we’re not about to begin to think about building life. And, if we build life, we’re not going to build it out of silicon anyway. So I just discount this for any foreseeable future completely.”
It is not a long interview, but does include some rational views on how nanotechnologies can help humanity, concerns over toxicity of small particles, and Whitesides’ views that we are probably smart enough to handle the creation of new materials, but perhaps we need to look at the secondary effects, such as the advances in data storage and its impact on privacy.