That won't ever happen. If you are using two different wallpapers, the icons will never fade in like if you're using the same one. That's why I use the same for lock and home. I really like the fade in.
Well I know it won't actually "fade" in but if I had the same wall but the apple logo was removed the apple logo would disappear and the icons would fly in. See what I am saying? This could only be achieved if I had the wallpaper before someone put the apple logo on it.