The reason I mention DNG is because it can be used as "superset" archiving format. It should be feasible to accept pretty much any kind of RAW in, archive a copy of the raw in the DNG (or just trust the conversion) -- and so let the users have an original on your servers. Again, not sure if you want to be a backup/archive for images, or just a point of publication (for me that is all that jpeg/png will ever be -- and it's not really something I am interested in paying for -- I would still have to deal with the headache of "publishing" from my Digital Negatives -- and maintaining that collection).
As camera technology continue to improve and storage continue dropping in price (at least on the camera end, flash cards etc) I suspect more and more low end cameras will support some form of DNG-format.
As camera technology continue to improve and storage continue dropping in price (at least on the camera end, flash cards etc) I suspect more and more low end cameras will support some form of DNG-format.