Nintendo Japan has officially announced the event by opening a website for the conference which they've described as a "Nintendo 3DS new product announcement conference." They'll also be streaming the conference from their website. (The stream link will be there the day of the announcement.) It will be Japanese so you might not understand it all, but you will be able to see what this new product is.

It all starts on September 13th at 12:00 noon in Japan. That's 11PM on September 12th Eastern US time.
http://www.nintendo.co.jp/n10/confere...
http://www.pokesplosion.com/
So, what do you think the new product will be?