In 2008, the World Health Organization (WHO) released the report of its Commission on Social Determinants of Health--Closing the Gap in a Generation. We describe how the report was initially received, what went into shaping the report during the months of its preparation and what more can be done now to realize the ultimate goal: population-level reduction in inequalities. As we find the Report to be strong in its presentation of evidence but weak in its policy recommendations, we present our own recommendations for research and action. From our perspectives within the increasingly visible field of social determinants of health research, we address this question: how can research improve the ability of public health policymakers to implement the Report's suggestions, plus develop new and better ones?