Developers have planned the Incheon region as the Korean answer to Asian hubs like Hong Kong and Singapore. They expect a lot of income from tourists in transit, wanting to kill some time and spend some $. The airport was finished ten years ago, and already serves as the main international air hub for all of Korea. The first stages of the three 'new cities' have been completed, and the government together with the developers hope to have realized the following artist's impressions by 2017 (I've also read 2020 somewhere else, but both seem rather unreachable to me). Songdo (one of the three new cities) for example is now home for 18.000 people, but is meant for 65.000 people. That means only a third of the project has been finished over the last decade.
Someone coined a term for (over-) planned hub-cities like Incheon: "
aerotropolis":
Today, the ubiquity of jet travel, round-the-clock workdays, overnight shipping, and global business networks has turned the pattern inside out. Soon the airport will be at the center and the city will be built around it, the better to keep workers, suppliers, executives and goods in touch with the global market. This is the aerotropolis: a combination of giant airport, planned city, shipping facility and business hub. (source)
The first two designs are by Daniel Libeskind.
