Looks like an online magazine site seems to think they have the inside scoop on the Nintnedo Revolution controller. Sounds interesting, and I sure hadn’t thought of this, yet somehow if this is all the controller is, I would feel a bit let down. Quote from Computer Games Magazine:
It's revolutionary in the same two senses that controller rumble is/was revolutionary: first, it's kind of actually not a huge deal, but controllers will eventually all have it because it is pretty neat; and second, it involves revolving. Simply, the Revolution controller will provide resistance to being tilted. No doubt this is done by some application of a tilt sensor such as the one in WarioWare: Twisted combined with rumble technology.
After all, rumble is just done by some off-balance widgets inside the controller spinning really fast. If they were balanced, they could provide enough rotational inertia— the same thing that makes bikes and motorcycles harder to tilt the faster they're going— to perform this trick.
The "could" is why Nintendo hasn't come out with it yet. Yeah, they say they don't want it to be copied, which is valid because I'm sure it will be, just not anytime soon. What's really happening is Nintendo is trying to make this work with wireless controllers, finding the optimal tradeoff between spinning the widgets fast enough to produce a good, strong effect and keeping the controller from eating batteries too quickly. Oh, and it has to be cheap and reliable, too