Well, I'm not that sure about that. CD-ROMs are not exactly punch cards; they are (or probably were, before DVDs became popular) considerably more popular. Punch cards were used by large, noisy computing machines that took a whole building and cost a fortune; CD-ROMs are used by small desktop computers that are not particularly expensive, and most people in somewhat developed countries do have one. It's probably more like finding a 8mm film or Beta tape labelled "Home movies" -- both technologies were quite widespread, so it should be quite easy to find a conversion service. And probably even that would not be needed: many computers still have 3.5 inch floppy drives, even though a good share of those drives never see a floppy. It's there just for backwards compatibility with that old format that was so popular that people still might need to read the occasional floppy.
Originally Posted by Sjixxxy
However, there's another archival issue, probably more serious than that -- CDs and especially DVDs should really be handled with care if you want them to last. For example, I have a pretty large collection of CD-Rs, and some of them cannot be read some three years later, even though I didn't do anything that bad to them. It's probably some 20 or so out of 500, but the number would surely grow with time. Backups, however, would help somewhat, and regular migration to newer formats would pretty much solve the problem.