According to IGN, there were whispers on the floor of the Game Developers Conference last week. Whispers about the Wii's upcoming MotionPlus accessory, and how it would ship in a rubber jacket.
So, unlike the rubber jacket that's currently available for the main Wii Remote, this one "might ship infused inside of a jacket and cannot be removed".
Less of a rubber condom, then, and more like a rubber straightjacket.
Things We Saw and Heard at GDC '09 [IGN]