Personally, I would really like to see an all-in-one washer/dryer in the Sims4. I have one IRL and it works great, put in the laundry, have it run for a few hours, and then come back later with them all clean, dried, and ready to be put away. Just make the combo model twice as expensive as the two separate washer/dryers and it would be totally worth it.
Alternatly, it would be neat if there was an option to take a sims laundry to a laundromat. Basically click on the pile of clothes or the hamper, select laundromat as a way to clean them, the sim carries the laundry off the lot and spends some simoleons, and then comes back an hour or two later with the cleaned laundry to put away. Basically let people use the laundry system without necessarily having to place two bulky appliances in their house or set up a wash tub and clothesline.
