German gaming news site GameFront has a brief mention of Nintendo's unveiling of a headset for the Nintendo DS.
The Nintendo DS has had, since its original launch in November 2004, a standard headphone port with an adjacent proprietary microphone port. The common wisdom went that Nintendo would soon be releasing a headset peripheral designed to plug into both ports at once when it had a game that would make use of said peripheral. This year's release of Metroid Prime Hunters, with online voice chat between matches, seemed like the perfect candidate—but the opportunity passed with no announcement.
GameFront speculates the peripheral is being released with the intent that it will be used with upcoming Pokémon titles for DS, which will feature online voice chat. Nintendo unveiled the hardware at a dealer fair, and said it will be available in Japan September 14 for 1,200 yen. Nintendo has not yet made an announcement when or if the headset will be available outside Japan.