Self-destructing DVD's, CD's and hard drives would be the ultimate media storage for long term preservation. Now, before you go thinking I'm crazy and heading off to some other site that talks about good quality metadata and long-term storage devices and media please hear me out. I agree that having good quality metadata (information about your files and media) helps sustain them into the future, and that so-called archival dvd's will probably hold up longer than non-archival ones, but the point I'd like to make is what's so good about a DVD that lasts up to 100 years if in 100 years there are no DVD players or devices to read them?
Of course you wouldn't want your precious digital stuff to self-destruct out of the blue so it should have some flashing lights and alarm sounds that get brighter and louder the closer it is to its doom-day. This would give you a chance to migrate files onto a new self-destructing media storage device before the old one becomes obsolete.