Of course, you all realise how pointless this discussion is - yes?
I'm not talking about there being a world-wide
conspiracy agreement to have a minimum copyright period and the chances of changing it significantly have got to be minuscule.
No, I'm talking about science eventually solving the problem of ageing: people will live forever and life+50 will be forever+50. Companies will find ways to invest their copyright with an individual to take advantage of the law, but such people will live under virtual house arrest in order to avoid sabotage by competitors that want to utterly destroy the body and so release the copyright in 50 years time. There will be privacy arguments over whether the law can demand a person appear in person to prove that they are still living and therefore still capable of holding copyright. There will be even more legal arguments over how much of a body must exist (kept alive artificially) to keep their copyright active, with counter arguments that all humans are now kept alive artificially by the genetic treatments that prevent ageing.
(
Oh man, am I cooking or what? ... Wait, has someone already done that? Have I just broken copyright? 
)