Originally Posted by ukbluetooth 
Now - how do we ensure that the digital media we record today will still be pristine in 40 years time?
That's so easy. Keeping backups and periodically refreshing them -- ie, if they're in a computer just copy to the new one when you change computers every couple of years. If they're on DVDs or other writable media - don't trust it - make fresh copies every couple years and keep multiple copies.