Details concerning the 3DS circle pad expansion have been released, provided by Nintendo after their press conference earlier today. It's set for release on 10th December in Japan, to coincide with the release of Monster Hunter 3 G, and will cost ¥1,500 (around £12).
It's been confirmed that the peripheral is powered by one AAA battery, rather than the 3DS's internal rechargeable battery. There are also a number of titles confirmed that will use this expansion, including Resident Evil Revelations, Metal Gear Solid Snake Eater 3D, Ace Combat 3D Cross Rumble, Dynasty Warriors VS and Kingdom Hearts 3D. All of these titles will have a logo on the packaging to show compatibility.
So, that clarifies some of the rumours and speculation. Is this expansion on your wish list along with these games?