We know the next Genesys book is going to be built on the Twilight Imperium setting, and will cover the CRB's Space Opera setting. The developers have already done a lot of space opera/science fiction material with Star Wars, so it will be interesting to see what ground they'll tread with the book. Aside from an in-depth dive into the setting, which hasn't had a whole lot of lore, I'm curious as to what new mechanics will be worked on.
- Vehicle customization: Genesys refined the weapon and armor attachment/modification rules, as well as tweaking the vehicle rules. The Expanded Player's Guide introduced rules on designing our own vehicles, but there are no rules for allowing PCs to customize their own vehicles, which I think is indispensable in a space opera science fiction setting.
- Mass combat: Large scale battles fits well with the setting, and I'd be curious to see if they reintroduce or refine the mass combat rules from Star Wars. Stuff like the squad/squadron rules would also be interesting to see.