The next time you look at a game and think, wow, how much more realistic can graphics get, remember: somebody has wondered it before, and been answered by the crushing weight of time.
I am wondering if graphics will ever hit a plateau. Right now the only reason graphic fidelity in gaming isn't moving faster is because of console limitations. I would like to see the game industry hit a graphical plateau for 10 or 20 years so that they can focus on other content and aspects of design. I'm not saying it would be great, it might be awful, but I would like to see what would come out of the industry if there were a long term standardization of graphic fidelity.
On the other hand, games have been using directx9 for over a decade, so maybe I'm living in that plateau and just not aware of it. (but I don't think so)