I haven't seen it mentioned yet, but...
What if "One World" is an expansion focused on a more refined and better functioning multiplayer? Perhaps even social networking elements will be thrown into it; maybe we'll see a new Facebook icon on the top bar.
cry
The meaning behind One World could be that, right now, many (perhaps "most") players play their own singleplayer games a majority of the time -- their own little worlds. Expanding multiplayer and polishing it up would open up many more players to it as groups play in "one" world.
Though, along with this could still probably be some new civs, buildings, etc. But, no new game-changing elements on a scale similar to religion brought by Gods & Kings.
Perhaps the Pitboss some people have been waiting for will finally be introduced as well.
There's seems to be something a little bit "off" about the title. It's not as... I don't know, epic or elegant... especially for a game like Civ. Though, we "have" had simple titles in the past like "Conquests" or "Warlords". I just think if there's a chance that it entails new trade mechanics, colonization, discovery etc., more elegant and creative titles could've been thought up. Perhaps it's just me, though.
Anybody remember "Play the World"?
http://en.wikipedia.org/wiki/Civilization_III:_Play_the_World
Perhaps, we can expect things like that -- not only a refined multiplayer, but all kinds of new little game modes like capture the flag and regicide (kill the king/queen), etc.
Maybe it'll turn multiplayer more RTS'ish with real time play. Tech will be researched like how you "tech" upgrades in games like Starcraft, as-in a constantly filled progress bar depending on your science; instead of income and yields "per turn" it's "per x seconds". Okay... yeah... that's probably a bit much and I'm getting carried away, lol.
All of those types of changes would be on a level similar to releasing a new game, not an expansion.
Also, I'm not sure when it changed, but does anybody remember how Firaxis was looking for some type of multiplayer programmer on their Careers page? I just checked and it's not there anymore.
I hope many here aren't setting themselves up for massive disappointment. Personally, I would much rather have a traditional type of expansion like Gods & Kings too. But for some, I'm sure a multiplayer-focused expansion would be thrilling news. Which they're certainly due for.
I'll still gobble it up and buy it of course, heck, maybe I'd start playing multiplayer whenever I play Civ too.
Again, this is all just some more wild speculation to add to the mix. We'll all just have to wait and see what this expansion brings to the table. My younger cousin is probably going to PAX again, so I can release some juicy bits of news here again for details and things that aren't included in the expansion's announcement. (
http://forums.2kgames.com/showthread.php?119093-Civ-V-Gods-amp-Kings-at-PAX)