Several sources, including Joystiq.com, are today reporting the rumors floating around various message boards that Nintendo is discontinuing Dance Dance Revolution: Mario Mix because of problems with the dance mat. While Nintendo has yet to comment on these rumors, those who started them feel the fact that most stores are sold out of the game and that it's selling on eBay for almost twice the retail price is evidence enough to suggest a stop in production. We'll let you know when and if Nintendo has any official comment on this issue.