Scenery, post processing effects, FX effects, that sort of thing. But I doubt that will be possible or very limited with DX9.
But dang, what'd I give to see something like HBAO, HDR, bloom, dynamic lighting, multiple light sources, better explosions, flames, smoke, mort particles, water droplets flying through clouds, shockwave effects, 4096 textures, destructible terrain, ambient sounds, water that is actually water, new terrain types,snow, desert, tundra, motion blur, vignette, heat haze/distortion effects.