I wonder if the period of 2009-2015 will have a bumper crop of content entering the public domain in Europe because so many young people died in the Second World War.
Depends on the country: some have explicitly extended the copyrights for people who died in the war. For example, writers who died in active service of the French military have copyright for 100 rather than 70 years postmortem: http://en.wikipedia.org/wiki/Mort_pour_la_France
Presumably it was to not discourage people in the future from enlisting/responding to the draft for fear of copyright, and to avoid the "poor windows and orphans of the famous writers who died in the war". Maybe the French are different, but "will my copyright endure longer if I die" would not really be on my list of concerns in war.
Antoine de Saint-Exupéry is the only one on the list who I've heard of.
I think it was some kind of feeling of fairness: that, absent the war, they would've lived longer, so there should be an adjustment to make copyright expire according to when they would've "normally" died. On the other hand, that's true of any copyright system based on years postmortem: you could argue the same about someone killed by a drunk driver, or hit by lightning, or murdered. That's one reason I prefer publication-date-based systems rather than years-postmortem systems (the other reason is that death dates for lesser-known authors are often very hard to actually find, whereas publication dates are typically printed right in the book).
Plus, I think the argument is weaker when duration is already life+70. If it were, say, life+0, or life+10, you might have an argument about their widow/orphan, but life+70 is already enough to cover any survivors comfortably for the rest of their own lives. Life+100 gets into territory where their great-grandkids are getting the money.
