The lighting on the Silo's needs correction. If you take the fence posts for example, they are unlit on the side facing the viewer, as the light is coming from up the road over the mountains. The silos however are lit from both directions, take down the lighting from the viewer's side, don't be afraid to mess about with…
CURSES! Well, you can still use all those fancy terrain material ideas. http://udn.epicgames.com/Three/TerrainAdvancedTextures.html#Multi-UV%20Mixing:%20Reducing%20tiling%20through%20scalar%20mixing That for example, might help with the look at a distance.
Not to toot my own horn but my paintover had some explicit ideas that more than anything were trying to help you focus people's attention in a good way. Maybe it's just me but I really just want to see a meteor crashing into the ground and wrecking shit up. You've got the motion and anticipation going, but I still don't…
Just search for "fire" or "flames" in the UDK content browser. You should find examples. Just copy and tweak them. It need not be complex, just a high emisive value. You can even make the emsive color contribute to the lighting so it lights up the corn field.
Diver was onto a good point that the meteors should all be bearing the same angle. If you wanted to break up their directions, then simply break up the meteors, smaller pieces coming off will create a diversity in their sizes, I would also consider making a couple alot bigger, like armageddon size, worth messin about with,…