I hope that they do not try and put on an extra layer on the burger in order to make it look more attractive.
What they should do, is make sure their ingredients are quality, not just add another layer of quantity.
So no religion alongside techtree, diplomacy and social policies, thats ultimately only a new layer of micromanagement, with no assurance it will actually be any good gameplay in itself.
For me personally, loyal to a given religion (Jesus, Son of God), it will also lock me down into playing a certain way, with no intentions of doing it different in any games. Simple as that.
Espionage can be a good implementation and strengthening of diplomacy, it can raise the quality of an ingredient already in the game. So I hope they do something like that. Alot of the game right now ,is not knowing whats going on outside own borders. Would actually be nice if you could see the map of an allie, of somewhere you have an embassy, or sneaked in spies.
So you could see how their war is going, know that this civ is now attacking this civs city. More info on diplomacy as it is so very much in the dark atm. Very often, a Civ pops up, says lets declare war against this guy, you say no. Then another Civ pops up, asks for the same. You think, hey this is my friend okay I will join. Or opposite, you join a war only to realise you just stepped on your allies toes. When the screen is up you can't access any info and it turns into a guessing game sooner or later as it happens all the time. Diplomacy needs much more transluscense, in a better way than just sidebars and infoscreens. Make is so you can see allies maps for instance, show a Civs allies and enemies on the dialogue screen.
My guess is though, that they have improved the victory scenes.