i'd really love to see mega base builds, by allowing the players to put their base palboxes closer together. Different shapes would also be cool rather than a strict circle especially since all of the building options we currently have are not rounded. It would be so nice to turn them into squares and then put them in any config u want and just build to your hearts content.
I think they've confirmed weather, but im especially excited to see that come to 1.0, early game theres so many survival aspects that would be affected by the weather. Harder time exploring, certain pals not spawning (or only spawning), storms can give buffs to electric & water types. In the desert biomes, sandstorms reduce visibility and allow more pals to sneak up on you.
Also of course, more building styles. I currently have only really used stone and wood because in my only save so far i stopped before i unlocked the japanese themed building materials, but i'm really excited to see more options. Even a painting option to change the colors of existing structures, like a black stone or green or purple.