File formats (Score 1)

Even if the physical media are still readable, don't forget to think about storing and updating your video in file formats which will still be readable by future apps. I have text documents written in MS Works and the like on a Mac Classic in the early 90's which still exist, having been copied from drive to drive over the years, but are barely if at all readable.

Also, the BBC Domesday project is an interesting example of what can happen if you store something away in a proprietary format for too long.