Would it be possible to have dynamic footprints/tracks of any kind on snow maps with UE3? Maybe with a paralax bump to give the impression that it sinks into the ground (not sure if you can do that on the fly)?
It would be especially cool if this also applied to tank tracks and bodies when crawling in snow.
I'm guessing an easy argument against this to this would be to say "Stop dreaming, silly! That's waaaaaaay too resource intensive! The servers would smolder and die!

"
But lo ho ho, wouldn't this be possible as a client-side option (if they fade after 10-20 seconds)?