Nintendo didn't say so on stage during the pre-Tokyo Game Show 3DS press conference tonight, but it really is shipping that odd-looking circle pad add-on. The "extended slide pad" is up on the gaming company's Japanese home page right now, with a shipping date of December 10th and a price of ¥1500 ($19.50). There's also a list of supported games available, including Monster Hunter Tri G, BioHazard Revelations, Snake Eater 3D and more. It's powered by a single AAA battery, which our country cousins at Joystiq note probably indicates you won't be getting any extra playtime added to your 3DS by slapping this "boat" on the bottom. Check the source link below for the official info -- we'll keep our eyes peeled in Tokyo for North American release info and of course, the color matched Misty Pink edition you're already looking for.
http://www.engadget.com/2011/09/13/nintendo-3ds-circle-pad-add-on-is-official-ships-december-10th/