Wii MotionPlus + 6DOF Head Tracking

Let's recap.



Simple Head Tracking
As-is, Johnny Lee's simple head tracker can allow the player to lean, crouch, and jump without using any buttons or joysticks. In his setup, you still cannot look (up/down) or turn. (left/right) Even if you bind the handheld Wiimote to a "look margin" similar to the one used in Metroid Prime 3, there isn't enough practical function in it to convince developers to integrate head tracking into their games. With just leaning, crouching, and jumping, it's just not worth requiring players to buy additional hardware, even if it's just another Wiimote and a pair of infrared LED glasses.

6DOF Head Tracking
With Manuel Unternaehrer's 6DOF head tracker, not only can you do everything Johnny Lee's original program could do, but you can also look and turn. In effect, the head tracker becomes its own pointer, and the "look margin" from Metroid Prime 3 that was previously bound to the handheld Wiimote can be reassigned to the head tracker. Because the handheld Wiimote is no longer bound to a "look margin", it is free to be pointed anywhere on screen. Apparently however, this still doesn't offer enough immersion to warrant much attention.

Wii MotionPlus
Then the Wii MotionPlus was announced. Combine the hands-free pointer of the 6DOF head tracker with the one-to-one motion tracking of the Wii MotionPlus, and you get an unbound Wiimote that you can point not just anywhere on-screen, but anywhere off-screen as well. Imagine the level of immersion you could get out of that system. For example, if you know there's an enemy behind you, you can point the Wiimote over your shoulder and fire. Or if you know there's an enemy right outside your peripheral vision you could fire in that direction instead of turning to look. (without head tracking, you wouldn't be able to do this because the wiimote would have to be pointing at the screen at all times in order to look and turn)

There are a couple of distinct possibilities that are now open to us.

"Twomote"
If we only need bindings for moving and strafing now, (because looking and turning is assigned to the head tracking "pointer") we could technically bind those functions to a Wiimote's D-pad. If we do that, then we don't need the nunchuck anymore, and can finally start using two Wiimotes, one in each hand. (which I call "Twomote" Style)

Balance Board Centering
Until the price of the Wii Balance Board goes down, it is my opinion that developers should have this hardware be completely optional to full motion gameplay. Once the price drops suffeciently though, it is possible that developers could expect the player to use the Balance Board not just for its inherent features, but also as a "default" spot on the floor for the player to return to for centering. (really though, if the inherent features aren't used, players would be better off using something else to mark their "default" spot)

Head Tracking Kit
The cost to manufacture, market, and buy the necessary additional hardware required for head tracking -- namely the IRLED headgear and wiimote stand -- can be minimized. As you can see at the end of Manuel Unternaehrer's 6DOF head tracking video, the 3 IRLEDs are arranged around the rim of an ordinary baseball cap. Those LEDs could potentially be attached to clips, meaning Nintendo wouldn't have to sell goggles or glasses, they could just sell the 3 IRLED clip set and ask the player to attach them to a baseball cap they already own. (Nintendo could also sell their own caps separately or bundled without having to modify the cap in the slightest)

As for the wiimote stand, I personally have designed and successfully tested a wiimote stand made entirely out of posterboard which features simple construction, four pre-defined angles, and supports the weight of the wiimote beautifully.

Obviously, a commercial version would probably use laminated cardstock or something stronger but just as cheap, and use tabs instead of tape to hold it together.

Nintendo has no excuse now.