Nintendo has confirmed that Super Smash Bros. on the Nintendo 3DS has sold over 2.8 million copies worldwide. Those numbers include Japan, America, Europe and Australia, and it also factors in both retail and download sales.
Due to the game just now launching in North America and Europe, those figures are made up mostly of the Japanese market, who have had the game for about two weeks.
Super Smash Bros. on Wii U was also confirmed for a release on November 21st in North America, December 5th in Europe, and December 6th in Japan.