The new Rain looks really cool, but I think they should add one more thing:
It should interact with objects.
My idea are little raindrops on glass panes (especially in cars) and maybe some on your glasses. People who wear glasses know those ugly things :)
You would feel the rain around yourself way better and it would add a lot of atmosphere. If you think it's too annoying, they could have the drops only on vehicles, not on your glasses. And of course they should make it so that you can still see well what's going on around your car.
Furthermore, there shouldn't be rain in buildings...pretty obvious.
And maybe as a last thing little splashes under your foot. (maybe depending on whether it's dirt or a road)
If they implement all thins, rain could add so much variety to the gameplay because you can really feel how wet it is.
Have you looked at heavy rain in the night? Set Overcast to 100 and Time to 2am or so. The rain is really ugly. Just grey stripes on the screen, way to bright. You can't see raindrops at night as they fall from the sky. Please remove them when its too dark, but leave the sound in. To make the player aware of the rain, implement the footstep splash sound on wet ground, please!