MrJack5304 writes "According to Nintendo's official Press Release, the Nintendo Wifi service has logged it's 1 millionth user. In 5 short months Nintendo has reached 1 million users, and had 27 million total connections."
From the release: "Nintendo Wi-Fi Connection lets Nintendo DS owners log on cost-free to compete or interact in a variety of games, from racing in Mario Kart DS to community-building in Animal Crossing: Wild World. The 1 millionth user was a player in Japan, who logged on to play Animal Crossing: Wild World."
The release goes on to mention that Tetris DS and Metroid Hunters will also utilize the service.