I currently use a Canon DSLR and backup its CR2 files as well as Aperture-generated previews (JPEGS). I'm considering whether converting the CR2 files to digital negatives (DNG) would make more sense from an archival point of view. It seems that DNG is "open" and supported by many photography applications. Essentially, I wonder whether in 20-30 years time, CR2 will be a long-forgotten file format whereas DNG will be the archival standard for raw files. I'd be interested in opinions on RAW vs DNG and whether anyone knows what large organizations with an interest in preserving their digital photographs use as file format.