The practice of small molecule chemistry could be viewed as a mastery of self-organization at the atomic scale. Recent advances in nanomaterial synthesis has inspired attempts to replicate that feat with building blocks that are considerably larger, though still microscopic. Limited success in this endeavor reflects a host of new challenges, many of them dynamical in nature. We have explored the statistical dynamics of nanoparticle self-assembly in the context of two model systems, comprising chaperonin protein complexes in one case and magnetic nanocrystals in another.