I know about the very limited shelf-life of DVD-R's.
Some people claim that DVD-Rs will last only 2 years, but that isn't necessarily true - just as the same claim isn't true for CD-Rs. I have CD-Rs that I made over 8 years ago that work as well as they did the day I made them - and I've also had some early ones that were lucky to last a few months. The truth is that it often all depends on how they were burned, the drive they were burned with, the software used, the computer, and the discs themselves. In the long run, like almost everything else, I've found that it's best not to go with the cheapest but to buy a name brand whose products have stood the test of time.
As for DVD-Rs, the oldest one I've made is just about 3 years old now, and it still works perfectly fine. Only time will tell how long it might actually last. But unfortunately I've misplaced my I Ching wands, so I can't travel into the future to check out just how long that might be.
Check back with me in a few more years.