Vinnk of 4 color rebellion has put this milestone into perspective. The Wii now has two platinum titles 3 1/2 months after its launch. The GameCube had only one million-seller in Japan, Super Smash Bros. Melee, that took longer time to reach that point.
However, other titles are not selling nearly as well, including The Legend of Zelda: Twilight Princess. As arguably the only Wii epic, Link's adventure hasn't yet reached the half-million mark in Japan. In fact, it has dropped out of the top 30. Other Wii titles in that top 30 last week include Fire Emblem (23), Wario Ware (26) and "Eye sealed 21 field strongest soldier" at 30. (Did we mention we love Google translations?)
What does this all mean? Expect to see ample amounts of casual games -- in Japan, at least.