I've been obsessing over AI recently and was so excited to see this! The opportunities are endless~~ I think the biggest thing I'd love is a cutscene generator. Basically you put in a prompt like, "Harold finds a girl being attacked by a wolf and runs up to save her." It would put in the events of Harold, the girl, and a wolf, and then code in the moveroute and full dialogue between Harold and the girl, complete with face graphics.
For my situation specifically, I have the entire script for my game written with dialogue already. So I'd love to just paste it into the prompt and see what it does!