I was recently considering a few things, after Zeos' Water thread, as well as the one of the snow on the mountains, and some of the tidbits you provided.
Do you plan to have some sort of (for lack of a better phrase) "weather model" that will simulate more or less global weather patterns? I know you've discussed a climate model, but I don't think we've heard a whole lot about weather. Maybe I missed a thread though
Rain falling, snow, monsoons, hurricanes, the obscene number of tornadoes in Tornado Alley in the US ... could be a very cool and interesting feature. Not to mention lightning with realistic thunder claps