Responding to your edit: I don't think data.gov should be in the business of curating too aggressively. It delays data being released, and it brings in a lot

Responding to your edit: I don't think data.gov should be in the business of curating too aggressively. It delays data being released, and it brings in a lot of questions about the politics of how that curation is done. I agree, though, on the need for a variety of release formats, detailed descriptions of the data, open and versioned repositories, and the political clout to get the data all in one place. I think of data.gov as a layer below IPUMS - you go to data.gov to source your IPUMS-like project (or your company that's built around doing the detailed curation you're talking about).