I've only played a bit of the demo, but I can't understand why people talk so much about the combat and how much better it is. You can no longer have a stack of doom, but I don't think there's anything really inspiring in only being able to have one unit per tile. You can throw around the word "tactical" and whatnot, but I wish there was more to be excited about that this and various other new limitations.
It could be a huge thing, but now it seems (ok, tested only on Prince) that the AI simply can't handle this 1UPT thing. No wonder, defending against human without ability to stack units in city etc. really is an extremely difficult AI problem.