Honestly, I just hope it's something that would be moddable and that Ziggy finds an interest in after his awesome work on Far Cry 3 that made the game so much better. =)
The setting I don't personally care so much about, I just wish the game avoids feeling so "sandboxy & minigame"-based like FC4 suffered from, ie. you have these and these minigames splattered around that you can do, I want to feel a more adventurous and story-focused single player again, FC1 was best in that regard, since then it changes more into this kind of minigame-style game that distracts from the immersion you get into the game.
I also think the worldmap design got less and less "believable" with every new title.


