Metadata (data about data) in GIS is one of the biggest challenges in the industry. There is plethora of data creation but searching the right data is a nightmare as there is more noise out there than good data.
ESRI has not been playing an active role. I do not know whether it is deliberate or missed opportunity. With trends of cloud GIS one needs to craft and implement metadata standards for public consumption. ESRI as a market driver should play a lead role in preserving spatial data for long term. Metadata is one of the key areas it should focus on esp. for their online products. It directly impacts search and discovery of good and relavant data.