In the September issue of Scientific American, a number of articles cast doubt on certain aspects of nanotechnological building blocks promoted by the Institute for Molecular Manufacturing and the Foresight Institute. The organizations have responded with specific rebuttals to these articles and pointers to the previous literature on the subject.
Worth a look. I wonder which side of the debate Bill Joy supports ... if he supports the SciAm view, then is GNR a false threat?
A Debate About Assemblers