The BBC is running a warning from the Chief executive of the UK National Archives: "Unless more work is done to ensure legacy file formats can be read and edited in the future, we face a digital dark hole."
Think about it, we can still read 5,000 years old Egyptian hieroglyphs or medieval manuscripts but we can't access a file on a floppy disk, read a Betamax tape or a Philips CD-I... There is a danger of loosing our collective memory because we record it on highly perishable media. And the pace of change drives the cost of re-recording it again and again for national archives, who are often poorly funded.
I reckon that in 10 years time, it will be fashionable to handwrite letters again, just because it involves efforts and makes the recipient feel special. And your letter will be preserved for hundred years for posterity, unlike that "reply all" email.