While I can see the hex grid (no more stacks of doom), new combat mechanics and the other tweaks giving some life to the Civ franchise, I still don't see the underlying experience changing at all. It's still all too familiar for me. For example, I'm pretty sure we're going to, once again, see Granaries, Phalanxes, Carriers, Artillery, Philosphy, Monarchy, Temples and all the rest of the BS that I've seen in the game for years and years. After all, you can't really change the content of a game based on real-world history.
Elemental just has so many new features that Civ doesn't, even if the core game-play is still lacking. In fact, I don't really see Civ 5 doing anything at all that Elemental doesn't already do. In addition to all the 4x staples, Elemental has separate kingdom and empire trees, a magic tree, real tactical combat, integrated modding (where I don't have to search the web for mods), quests, unit customization, a customizable sovereign character, marriage, wives, children, dynasties, spacial cities, and role-playing.
Beyond that, Elemental just feels like a completely different experience to me than any Civ game I've ever played. I don't have to play Elemental and try to understand why Alexander the Great has Nuclear Weapons. I don't have to try to rationalize why I'm playing real-world history on some random-seeded map any more. Every experience makes sense in Elemental, because it's fantasy, and it's an experience and a story that I had a hand in making up myself based on a world that doesn't really exist. I can't mod in Goblins and expect it to make sense with my dragoons, but I can throw in anything my imagination can come up with in Elemental and it will still make sense in any game.
I won't argue that Civ 5 isn't going to be great, but I disagree that this isn't just the same Civilization packaged with a few notable changes. It's still 4X world history that has to adhere to certain rules and boundaries. It is a road that will dead-end at some point, while Elemental will not.