Now that we have downloadable/uploadable condos, a lot of people are uploading really nice theme based condos for others to enjoy. Something that I feel would work for a lot of condo creators (myself included) would be additional weather types for use in their condos.
Suggested New Weather Types from Me:
Sandstorm (Useful for Desert / Post-Apocalyptic Themed Maps)
Heat Wave (Useful for Desert / Daytime City Themed Maps)
Ashfall (Useful for Volcano / Lava / Nuclear Warfare Themed Maps)
Haze / Mist (Different than Fog [Oriented more towards the ground and close instead of the distance.] Useful for Swamp, Jungle, and Horror Themed Maps)
Underwater Filter (Useful for Underwater Themed Maps)
Radiation (Useful for Post-Apocalyptic / Horror Themed Maps)
Those are just a few selections on my end! I really feel like a lot of these would inspire some awesome customizable condos, and I think a lot of people would enjoy them heavily.