- If OpenGL handle that, it could be a nice feature.
- Motion blur too, particulary in 1st person view could be fantastic
It look like some games use blur to improve performances (like lowering by half the resolution for rear plan and applying a quick antialiasing on it).
- In other graphical improvement, dust clouds could be nice too. I remember some crazy starts in MX where i can see only my front wheel. This race was canceled because it was too crazy and dangerous, but funny to remember.