Once again, nano-hype. This time the subject is this very nice paper from Seeman's group at NYU, in which they use DNA-based tools to perform programmed self-assembly of some cute nanostructures (also made out of DNA). Seeman has been doing pioneering work for years on leveraging the great specificity of DNA chemistry to make interesting nanostructures. The trick is that each nucleic acid base in DNA likes to hydrogen bond with its own particular complementary base. This specificity of binding plays an essential role in eukaryotic biology, and we now know how to engineer it. In this case, Seeman and coauthors set up a situation where user-defined shapes made from DNA (created using "DNA origami") are bound in specific places and not elsewhere. The major innovation is that they've figured out a way to implement a form of error correction, and in principle they can alter the assembly parameters (that is, which peg goes into which hole) on the fly.
This is nice work, but it's not a nanorobot, not by any reasonable definition of the term. Sorry. By the way, the word "robot" doesn't appear anywhere in the paper (except in the title to one of the references).