Thin films of incompatible block copolymers self-assemble into highly regular supramolecular structures with characteristic dimensions in the 10–100 nm regime. There is increasing interest in controlling the resulting structures and utilizing them, for instance in the area of nanotechnology. So far, research has concentrated mainly on exploiting the melt structure of diblock copolymers. Recent work on block copolymer solutions and more complex co- and terpolymer architectures has revealed a rich variety of novel thin-film structures, some of which exhibit high complexity and order. In addition, by use of mean field dynamic density functional theory along with well-controlled experiments, the fundamentals of thin film structure formation have been elucidated. We highlight some aspects of these studies and point to future directions in this lively field of materials science.