Dragon Quest IX has sold more than four million copies to date in Japan, where the game's WiFi "Pass-By Guest" feature has proven very popular. North American gamers will get a chance to experience it as the renamed "Tag Mode," silently trading character stats, battle records and play data with other DQIX players simply by walking near each other with their handhelds in sleep mode. If you encounter a player who's logged more than 400 hours in the game, it's probably this guy.
You'll find pre-order information (and a rather delightful trailer) on the game's official website.
Update: Dragon Quest IX will be released in Europe on July 23.