Cheers for the list, SG-17.
- Switch from squares to hexagons changing the way the game plays. More room for maneuvers and more tactical options.
Technically there will be less since you can only move in 6 direction as opposed to 8, but the more I contemplate a hex board the more I like it.
- Changes to combat. More depth in combat, no more stacking of units. This will lead to bigger focus on terrain.
Excellent!

Unit stacking was very dull, all you needed was 5 or 6 bombardiers, 3 or 4 defensive units and a shitload of offensive units and you could destroy an empire. I wouldn't have minded unit stacks if they had implemented them the way they were in the Call to Power games, back when stack composition was extremely important, but in Civ 4 it came down to who had the bigger stack almost all the time.
- Reintroduction of Bombardment, now archers and siege equipment can shoot over melee units.
Good, good, I enjoyed that in Civ 3.
I'll believe it when I play it and Montezuma doesn't attack me completely at random. Better diplomatic AI has been promised since Civ 2, but they still act like vicious six-year olds.
- More diplomatic options between players.
Good good, I'm a builder so more diplomacy options is always a plus in my book.
Once again, they keep promising this, but the AI always resorts to cheating in the final product, especially at higher difficult levels.
- Religion is not a factor anymore.
That's a pity, I rather liked it.

I was hoping that they'd flesh it out and make the religions more unique, cutting it entirely seems like a step back. Or more likely, they're holding it back for an expansion.
- Ressources are not infinite. For example one source of horse only supplies enough horses for 1 unit, but when that horseman dies the horses will respawn as a unit.
Seems odd when applied to horses, but it is vaguely understandable when it comes to resources like oil.
- City States as a sort of small countries that never develop beyond their single city. They can provide bonusses if you befriend them, or you can take over their land.
Sounds good, I always wanted them to do something like this rather than the mindless barbarians we have now.
- Civics are out, now there is something called "Social Policies".
I liked civics, but I'll wait and see how this social policy thing works before judging the change. So long as they don't move back to the rigidity of government types.
- Some victory conditions changed. For example in Conquest you only have to capture all the other capitals. Eliminates boring mop up phase.
Very interesting, I can't wait to see how this will play out. Usually, once you take their capital they're already defeated.
There's no mention of the one thing I loath about Civ 4: the AI spamming cities all over the place, especially annoying when they sneak around your empire and place a lone city cut off from their empire and demand open borders to reach it. Hopefully there will be enough city states in the game to prevent things like that from happening.
Overall, I'm looking forward to it.

I just hope that my PC can handle it without any major upgrades.