According to this, Nintendo Korea is likely to launch Wii in South Korea before the country's Children's Day, which falls on May 5.
As the article points out, piracy's a massive problem in Korea, an issue Wii is unlikely to be able to shrug off.
"Even before its official release, many game shops in major electronics stores such as Yongsan and Kukje Electronics Market have been selling imported Wii players that have a special chip transplanted to run duplicated game CDs," said the story.
Have a read. Interesting stuff.