It was interesting to see the distribution. Over half of the participants chose five years or more, so most people doing this are thinking in the long-term.
Many projects were done at the turn of the millennium with traditional hole-in-the-ground time capsules. The new idea is to have the capsule be completely electronic, instead of in the dirt.
If you bury something underground, that's a great way to preserve it, but if you store something in a hard drive, anything can happen from computer failure to network changes. The way to make it work is to encourage redundancy.