The potential medical applications of microarrays and in vitro diagnostic devices for global assessments of DNA sequence variations, relative RNA abundance and measurements of proteins have generated much excitement, and some skepticism, within the biomedical community. It has been suggested that within the next decade these microarrays and diagnostic devices will be routinely used in the selection, assessment and quality control of the best drugs for pharmaceutical development, at the bedside for diagnostics and for clinical monitoring of both desired and adverse outcomes of therapeutic interventions. Realizing such potential will be a challenge to the entire scientific community as often breakthroughs which show great promise at the bench fail to meet the requirements of clinicians and regulatory scientists, and to make the transition into common clinical and regulatory practice. The development of a co-operative framework between regulators, product sponsors and technology experts will be essential for realizing the revolutionary promise these platforms could have on the evolution of drug development, regulatory science, the practice of medicine and public health.