Although Nintendo has not made any official announcement, the Wii has now passed the total cumulative sales of the GameCube in Japan according to sales data released by Famitsu.
Famitsu reports that the Wii has now sold 4,025,356 units in Japan.
According to the most recent data released by Nintendo, the GameCube has sold 21.66 million units worldwide as of September 30, 2007. 12.88 million units were sold in the Americas, 4.02 million in Japan, and 4.76 in other regions.
MediaCreate's sales data differs from Famitsu, but still puts the Wii within 100,000 units of the GameCube. At the rate that the Wii has been selling in Japan, it should take only a few more weeks to surpass total GameCube sales.
The Wii was launched in Japan in 2006; The GameCube was launched in Japan in 2001.