The process of mRNA decay is integral to the post-transcriptional control of gene expression. The enzymes of the pathway have been identified, and now several laboratories have found that the mRNA decay machinery is localized to discrete cytoplasmic foci whose existence had not been suspected previously. In addition, we can now see that mRNA turnover is a means to coordinate gene expression, first through integration with control of transcription, export and translation of mRNAs, and second through enabling mRNAs involved in similar processes to decay at similar rates. These and other aspects of the field are discussed.