Dealing with "PC Abandonware" daily, I can assure you games like Doom and Quake are by now considered "retro" and "classics". The only reason you can't find them that often is that id is still making money off them. Here is the collection of a site which is pretty typical for the 'new generation': Battle Arena Toshinden 2, Blood, Carmageddon, Command&Conquer Gold, Commander Keen 1, Commander Keen 4, Descent, Destruction Derby, Destruction Derby 2, Dune 2: The Building Of A Dynasty, Fatal Racing (aka Whiplash), Golden Axe, Grand Prix 2, Leisure Suit Larry 1 (Remake)
Leisure Suit Larry 6, Magic Carpet, Magic Carpet - Hidden Worlds, Magic Carpet 2 - Netherworlds, Need For Speed 2 - Special Edition, One Must Fall 2097, Pizza Tycoon, Street Rod 2, Theme Park, Turok: Dinosaur Hunter, Virtua Cop 2.
It always pains me to see such (to me) new games being treated as 'classics' (because to me, they're just uninteresting crap), but apparantely, it is different with other people. I'm convinced that to most people who are into 'retrogaming' defined as most people do here will not 'switch' to anything else anymore. For a 'younger generation', these newer titles are 'retro' already though, they won't get into 'our' games though.
Even newer titles will become 'retro', too. Only again to another bunch of people. The world moves on - but people do not.