Will not happen. The new formats are pretty different than the old formats.
Any ideas on what media to backup one of these things?
Other harddisks. The cloud will be a huge one and there will be millions of clouds.
Does anyone with a "real" life actually need to store that much data?
Yes. We have institutions like for instance CERN who produce massive amounts of data each and every second. Todays research is tomorrows data. Just because the human brain cannot comprehend it, that does not mean we will have no use for it.