2K Games PR Manager Brian Roundy delivered the bad news: "Civilization Online is developed by South Korea-based XL Games in partnership with 2K, and will be available first in Korea. No release date has been set. There are no plans for a North American release at this time."
This doesn't mean all hope is lost, of course. It might be that the studios are holding their cards close to their chest or that they don't want to commit until they see how it performs in Korea. But if you were camping in front of a retail store (why?) for this release in America, you should probably go home for now.