There are a couple things that I'd really like to see, that would make the game more enjoyable, IMO, no matter what, where or when you're flying/driving...
First is something I've never really understood. Your plane shakes when your shooting, but not when it get's hit? I think a vibration, similar to but more severe than the one you get when you fire, would really add more of an 'oh sh-' factor to being shot at. Perhaps it could jar your gun when you're in a tank, as well.
Next I think would be an obvious evolution, but one I'd rather seen implemented sooner rather than later; update the fire, smoke, muzzle flash and tracer effects. In my opinion these effects more than anything else are what keeps this game *looking* like a late 90's game rather than a late 00's game.
Another thing I'd like would be something added to skins; some kind of alpha file (I guess you would call it) that would allow a skinner to assign different material values to different areas of the skin. This would affect aircraft that have a combination of paint and bare metal the most, but everything would look better if one area, like a wing could be moderately shiny, and a tire or exhaust stained area or what have you would be completely flat.
