This week I've read about a couple of new technologies that, together, seem to pretty clearly be the effective dawn of the nanotech era.
The main ideas are:
1. We can successfully assemble DNA from scratch in desired configurations
2. identical strands of DNA seek each other out and bind in a solution
3. DNA can be bound to molecules, and using the property in number two the molecules can be arranged in three dimensional shapes.
4. Heart muscles can be arranged in strands that continue to live and contract in along a desired axis in the presence of low voltage electrical pulse.
5. The strands of heart muscle in number four can be used for mechanical energy in tiny machines, and they can live off of the sugars abundant in blood.
6. Nanotubes of arbitrary length can now be constructed.
7. The genes that coral animals use to construct hard cell membranes out of silicon have been decoded.
Put it all together: We now have the knowledge required to assemble and power molecular machines. Where's the weak link? Sounds like design. It will still take alot of computing power to know what structures to assemble and do the brute work of getting it all to work together. And for that, the intermediate stages of the technology will certainly help. I would roughly guess that we could expect to see "grown" chips within two or three semiconductor cycles, and applications in health in just double that. Which, turns out, is right about in line with Kurzweil's predictions.