cost and just cost…

EXCELLENT POINT! Bonded macroscopic assemblies of carbon nanotubes promise to make use of the strongest bond found in natural stable matter, the Carbon-Carbon bond. I also think that nanotechnology will enable us to have active materials, imagine diamondoid and fullerene composites that also incorporate motors and actuators and such in their lattice structures, so they can move and repair themselves, and more, according to pre programmed instructions.

What's surprising is that, even though carbon nanotubes are a major part of nanoscale bulk technology, they are not mentioned anywhere in the article as a possible material with which to construct bridges. Carbon nanotubes are much stronger than any steel, including the nanoparticle-reinforced steel mentioned in the article. Also, research is being done to find non-MNT methods to mass-produce carbon nanotubes.

> Both concrete and asphalt are nanomaterials

This is really getting out of hand. Before too long we shall be calling every material "nanostructured". After all, wood is composed of cellulose with nanoscale features, polyethylene has nanoscale packing irregularities (removing which produces an incredibly strong material), vulcanized rubber has nanoscale sulfur bridges that keep it together, silicone microprocessors have 130 nm features, optical data switches work with radiation of nanometer wavelength. Even cooking is nanotechnology, because it changes matter at the nanoscale by denaturing proteins (cooked meat), creating self-assembling nanoscale foams (whipped cream), aligning nanoscale gluten fibers into a flexible air-trapping material (kneading dough), using nanoscale carbon dioxide generators to add fine structure to this flexible air-trapping material (yeast rising), and finally, using thermal protein denaturation (baking) combined with an ingenious form-constraining technology (the bread pan), producing a nutritions nano-featured meal. If you have a lot of imagination, you can apply "nanotechnology" to pretty much anything, which in the end will mean absolutely nothing.

This is all bulk technology – it's not true nanotech or MNT. It's not news worthy.