I'd prefer seasons, but some sort of weather is a must for the TS5 bg. TS is the only game I know of that charges separately for weather/seasons, and I'm not a fan.
I'd also like to see bg laundry and hot tubs. While laundry day has some beautiful objects in it, I really hated how it was presented to the community, as it was something many had been wanting, and naturally won, even though it doesn't really fit the eco-living theme. I'm not going to be surprised when TS5 inevitably has laundry as an expansion though...
I also agree with the OP about cars, and more than one family being able to live on a lot.
