The NASA Atmospheric Infrared Sounder (AIRS) satellite instrument has been provided near-continuous infrared spectral observation of the Earth since September 2002. Retrieved quantities from AIRS and its companion instrument the Advanced Microwave Sounding Unit (AMSU), include detailed information about profiles of temperature and water vapor, the abundance of trace gases (ozone, methane, carbon monoxide, and carbon dioxide), and surface and cloud properties. We describe updates to the AIRS/AMSU retrieval algorithm and the resulting Version 6 data set, planned for release in early 2012. We also discuss the implications of these algorithmic changes for the understanding of weather, climate and atmospheric composition.