Currently we have weather effects such as rain and I'm sure that it will be no different in 2.0. However, how cool would it be if after a certain period of time of your character running around in the rain you can see water dripping off your armor. And better yet, in combat, it would look amazing if while you swung your weapon doing a WS where you can see particles of water just bursting off your blade. Or for ranged attacks you can see the arrow cut through the water. Even if they see this I don't know if they would consider it, but it would make it look pretty cool.