How long will CD-R's & DVD-R's last?

Nobody knows.

I just hold in my hands HP 650MB CD-R that I burned in early 1998. It is almost 9 years old and sounds fabulous. I also have many DVD+R disks burned more than 3-4 years back. Every disk is like new.
Greetings
Plutos

These are the Disc made in Japan. Maxell and Sony made by Taiyo Yuden.

You can no longer be certain that media from Maxell and Sony is genuine Taiyo Yuden media (definitely an excelent manufacturer). I've bought Sony DVD media that I discovered was of the worst quality manufacturing and was made in Taiwan. More than half of them would not burn and ended up in the circular file (pun intended). I think more and more the larger manufacturers are shopping for the best price and not necessarily the best media. I've recently started buying media from Supermedia Store where you can buy unbranded Taiyo Yuden media, as well as having other good media selection.

Marco

From the Supermedia Store site here is a link to detect real from fake Taiyo Yuden media.

Marco