I imagine that those who will be studying our culture and society in the future will be quite thankful if we manage to save as much of it as possible, down to the most inane Twitter post. In terms of culture and society, the shift from mass print to electronic may prove to be as important as the one from writing to mass print and people will probably want to examine it in the future. As grandparent mentions, the BBC and Hollywood wiped stuff that we now think is important. We can't say for sure what will be important or not in a hundred years time. Although I'm fairly sure that anything Paris Hilton tweets will probably still be as pointless as they are today.