A humble non-nerd wonders about disc types. (Score 1)

All I can add to this thread is to say that MP3 has been fully embraced by all the young music fans and preformers.This holiday season will really put them on the map. As the father of a pretty hip teenager, I can tell you it's very very popular. Especially the downloading of music free or not.
With collections growing, which disk will prevail? SanDisk, Iomega, somebody else? What's a layman to think?
I don't want to end up buying something that plays "eight tracks" when "casettes" are the next format, excuse my outdated analogy.