The Evolution of the Revolution
Jane Pinckard, over at 1up, has a look at the evolution of the Nintendo Revolution controller...not that we have any real idea what the revolution will be. She takes a look at what we know to be untrue, and speculates on what might be. From the article: "One natural line of thinking, after eliminating the buttons and the D-pad, was that the controller would be touchable - not a far-fetched idea, since the DS uses a touch screen. What could be more intuitive than the power of touch? Throw in the microphone - another DS feature - and you have this model featured on the right; the creator kept the buttons and the analog stick, possibly to enable backwards compatibility. But the main interface of this controller concept is the spacious haptic touch screen."
I've been using a keyboard from Fingerworks http://www.fingerworks.com/ (that now looks shut down), that has no actual keys on it. The included gestures are very easy to learn, and you can even make your own. Because of this, I don't see a d-pad less controller too far of a stretch, though extreme precision might be tough to achieve without lots of practice.
Hasn't Nintendo stated multiple times that the Revolution won't use a DS-like controller? Besides, anyone who's played Wario Ware: Twisted knows they're going to do a gyroscope anyway.