Well, this was unexpected.
A European patent held by Nintendo (discovered by Siliconera) shows the company isn't content with just having peripherals like the Balance Board, Vitality Sensor, Zapper, Wheel, MotionPlus and the Nunchuck. No, Nintendo wants to peripheralize your badonkadonk as well.
An inflatable horse saddle is the latest innovation patented by the company. The seat would have be able to sense body motion through built-in sensors and present an accurate translation on screen, like a MotionPlus for your butt.
In the picture, a child is seen holding a nunchuck, which the patent describes could be used for "bronco riding, a lasso, a sword, or other weapon."
Keep in mind that just because Nintendo has filed a patent doesn't mean the peripheral will actually be developed or released. Still, Yoshi's Safari Wii confirmed?