I've been working with recordable media for 20 years and I've heard hundreds of claims like this and all of them are little more than speculation. When commercially pressed CDs were first marketed they were touted to last 100 years, currently I have pressed CD-ROMs of only 10 years of age that are completely unreadable. The fatal flaw in all optical discs is the layered construction, an acrylic layer, a dye layer, a foil layer, and a lacquer layer. No matter what the dye layer is made of the layers will eventually seperate due to various chemical processes, and if that doesn't happen over very long periods (30+ years) then eventually even the most durable layer, the acrylic, will warp, yellow or become opaque. Most of the long term studies I've read recommend tape storage as the most reliable method of archiving massive amounts of very important data. I use DDS on my workstation to archive photos because it scales well, and offers the best reliability for the price. Unfortunately, tape isn't the best option for every situation, storing 26PB of data on 170,393 160GB DDS cartridges would be a nightmare, but probably not as bad as writing 6,224,423 single layer DVDs. However, if one must use DVDs, the best option I've come across so far is Mobile Fidelity's 24K gold Ultra Discs, the price is a lot better at $4.99 each and they can be read or written on any extant CD/DVD-R drive and (based solely on my experiences) tend to hold up much better than store bought media.