Do you mean in terms of lighting? Because I think that would require a new graphics engine, and would require quite a bit of work... However, I have been wrong before.
One of the cooler effects available in most games (in my opinion) is something called "bloom." This effect basically simulates the bleed effect around bright objects and makes them look very real. I think this effect could make bright objects and reflections look a bit more convincing. It does take a bit of power for the computer to render, but in every case I've seen, light bloom was an optional effect.