The prospect of nanopores as a next-generation sequencing platform has been a topic of growing interest and considerable government-sponsored research for more than a decade. Oxford Nanopore Technologies recently announced the first commercial nanopore sequencing devices, to be made available by the end of 2012, while other companies (Life, Roche, and IBM) are also pursuing nanopore sequencing approaches. In this paper, the state of the art in nanopore sequencing is reviewed, focusing on the most recent contributions that have or promise to have next-generation sequencing commercial potential. We consider also the scalability of the circuitry to support multichannel arrays of nanopores in future sequencing devices, which is critical to commercial viability.