Your scenario where nano (or gm) technologies insidiously weave themselves into the very fabric of our societies, right into the food we eat, is already well underway and I suspect there’s little we can do — short of the revolutionary — to prevent it. I’ve read a number of people suggest that the silver lining to be found on the cloud of peak oil will be a rapid deceleration of this kind of development.

Of course, the unintended consequences we may face in twenty years will already have been set in motion today. So damage limitation may be the best we can expect.

On the other hand, there’s a view that a period of radical economic upheaval might see scientific research and investment focus even more keenly on the sort of esoteric fields that could give rise to the visions of Kurzweil or Drexler.

When you boil it all down, Joy’s basic concern was that we might develop a machine or organism (or combination of the two) which would out-compete us for the resources we need to survive. I honestly don’t know how far-fatched an idea that is, but I do recall reading science-fiction as a kid and mentally consigning “cloning” to the “time travel / never happen” category.

Whether it’s a voracious super-locust engineered to be nigh indestructable through a combination of genetics and nanotech armour, or a swarm of self-replicating robots, the unintended consequences of corporate research into non-fossil-based pesticides will be, almost by definition, hard to predict.

So if our nanotech toothpaste hasn’t given us all brain cancer within 20 years, then the gray goo could still get us!

The situation is much more likely to be the familiar one in which a new tech vastly undershoots the potential originally envisaged for it, makes a lot of money by adding small modifications to existing products, comes up with a few interesting new applications, and drives a steamroller through a lot of non-technological institutions, such as intellectual property law.

That’s where the ‘revolutionary’ stuff will happen, with all sorts of big unintended consequences.