Well using new polygons in ash would be good only here:
So I dont think its gonna change gameplay so much... We need to see that after a few weeks of playing :]
PS now its look like mist... in some way that is awesome idea. You need to check how it would look with a bit darker background and some fog below... Just for funn.
PPS did you though about adding edges?
its look good with them, add some contrast to texture, even if its a bit cartoon'ish.
no edge:edge: