I can agree with Aaron to a degree, but I feel that "demand" for games to improve from the established mechanics that have worked in the past has increased with each passing generation, rather - Void and Lion mentioned - the "quality" of the games.

Final Fantasy VII seems to be the main example/scapegoat for this comparison, but let's remember why pundits of VII still consider VII one of the greater RPG's of all time, not because of graphics, but a combination of great game mechanics and immersive storytelling, even if the graphic element hasn't aged out well.

---