I would love to see a hot killer island. Perhaps a large desert, cactus, some bushy sections, 0-1 trees, constant high temperature and only 1-3 dry berry bushes with no rain (or maybe a short rainfall every 20-30 days?). It could be cool with new creatures for that too, maybe a pack of coyote-like enemies. I'm still quite short on this idea though.
~ I also have no idea how much time and resources the team need to use to make new islands