I know Far Cry 2 had plenty of flaws but I enjoyed it and I'd really enjoy another African game.
It's probably not going to be Far Cry 4 (since going back to the jungle island turned out so well) but I'd like a game that tackles one or more of Africa's issues.
Things like poaching, African superstition (e.g. selling Albino body parts), oil, the growing threat of terrorism in Africa or China in Africa.
There doesn't need to be any preaching, it just needs to be a good shooter with these things going on in the background.
I'd really like a game like that.