When John Demjanjuk, an 89-year-old Nazi war-crimes suspect, goes on trial in Munich, he will be among the last few people to face these kinds of charges. And not just because of the advanced age of the criminals who committed atrocities in WWII.

"You can't just have a trial with documents," Rabbi Marvin Hier of the Simon Wiesenthal Center told CNN. "You have to have living witnesses. Most of those witnesses are very old, most of them are well into their 80s and beyond and they have to be in sufficient good health that they can be questioned and travel to take part in the trial."

And really, before long, everyone who was actually in Nazi-ruled Germany will be gone -- the victims, the criminals and the bystanders.

So what happens next? Will people stop caring? Or will they start to care more? Will the passage of time make them more sensitive to these kinds of atrocities? (Hey, remember Darfur?) Or is the Holocaust going to pass out of living history and start to seem like just words in a textbook?