Something must happen to some CDs... I've got a couple of music CDs from the early 1990s that I've only used a few times (without fault) and when I came to rip them to MP3 recently they were all messed up on the outer tracks. The inner tracks ripped fine. And these are stored in dark, room temperature conditions. Ah well...

As for collecting, the systems and targets of the people will change, but I think there will always be games collectors. I'm not sure though what will happen to the systems that pass out of the light, after all at some point the 2600 set will dwindle down to pretty much nothing as everyone gets quite older. We've not reached the point yet for any system to say what will happen.