Grey goo probably not a problem

According to the article Safe exponential manufacturing in Nanotechnology v15, Aug 2004 by Chris Pheonix and nanotech guru Eric Drexler, the threat of nanotech turning the world into a indistinguishable mass of grey goo isn't as bad as they had thought, at least by accident. Oh well, there goes the plot of half the SF novels of the past few years...

The conclusion:

Early proposals for manufaturing systems based on molecular nanotechnology inlcuded devices that had some similarity to runaway self-replicating machines, in that they were, at least, self-replicating. It has since become clear that all risk of accidental runaway replication can be avoided, since efficient manufacturing systems can be designed, built, and used without ever making a device with the complex additional capabilities that a hypothetical "grey goo robot" would require. However, this does not mean that molecular nanotechnology is without risks. Problems including weapon systems, radical shifts in economic and political power, and aggregate environmental risks from novel products and large-scale production will require close attention and careful policymaking.