Hard to say whether there will be tons of people who would really call themselves a collector of them. I have more 360 and Wii games than anything but that is more attributed to ease of access. I can run to a Gamestop and pick up 10 360 games for $50 if I look hard enough, whereas is if I want 10 SNES games I can reasonably expect to pay $200 because I have to turn to eBay or a Play N Trade, which is getting harder to find. Geographically, it might hurt me that there aren't many of the places I see here like Value Village or Savers in the entire state or even a bordering state. Here in NJ, we have maybe half a dozen PnTs and some thrifts/pawn shops but a thousand Gamestops.
I think 10 years from now people will have more PS3 etc games than others simply because it has become more, and I hate this word, "mainstream" to play games. 20 years ago when I was a kid, it was more of a niche hobby and 20 years before that forget it. But to think people would call themselves a PS3 "collector" seems crazy, but likely.
agreed with everything you said. as far as price- there's a myriad of reasons why X game costs a certain amount, but I wonder if the reason that old games tend to be pricier than new is because people are retaining them more and thus the amount that are being sold/traded is lower, or because they produced less of them? I know that they sold a million copies of Super Mario Kart, but you could go to any store or garage sale in my city with a population of 65,000+ and you won't see a single copy for sale. But I really can't imagine they produced a ton more copies of Mass Effect (an equally good game) that the price for Mass Effect would be THAT much lower. I'd be very curious to see production numbers for that game- I know it's one of the best selling games of the last 7 or 8 years.