I have thought about the difficulties of long-term storage for a while, and have come to the conclusion that digital mediums are inherently a poor choice for archiving and preserving data:

http://howicode.nateeag.com/data-preservation.html

As one of the more recent additions to that essay shows, I'm not the only one with that opinion:

https://partners.nytimes.com/library/magazine/millennium/m6/...

As I note in the essay, there are some technologies that work better than others for preservation, but digital's biggest weaknesses are inherent, I think.