If only we could ride furnitures like that bicycle, the tricycle and that MK7 kart, I hope they will add rideable vehicles like that on the next AC game, imagine a dirt road on your town so you can race with other villagers on little ATVs, or have a little kart track, and use stuff like skateboards and bicycles for faster travel anywhere.
Another thing that could be nice is better interaction with the furnitures, like taking a bath on the bathtub, get a coffee mug and fill it with coffee with a coffee machine and drink it, use a computer to order furnitures and check e-mails as a replacement for the mail boxes, cook fruits with the kitchen furnitures, wash hands on the sink, eat a bread from the toaster, among other things that could make most of the furnitures on new leaf useable instead of just being a decoration.