As innovative as the Nintendo Wii input controller is, the basic mechanisms for how it works will disappoint some users of the system and limit some of the imagined uses for this device in the near future. However, it presents a great opportunity for some break-throughs in the virtual experience.
Nintendo deserves lots of credit for their innovation here. In a market increasingly focused on sequels (rather than break-through titles), the gaming experience as a channel for selling other goods and services (e.g. in-game advertising), and an obsession with higher and higher resolution graphics.....Nintendo managed to make an inherently visual/audible experience more fun physically.
However, some of the enthusiasm for the Wii controller appears to be based upon how we hope or imagine it works and not as much on how it actually behaves....at least for now.
At their foundations, most games execute player movements in a very defined manner - e.g. press some key on your game controller and the on-screen character strikes with a sword in a downward movement, press a different key and they strike with a horizontal movement from the left, press another key and they strike with a horizontal movement from the right. These movements are very defined in that the angle of the attack is 0 degrees (overhead), 90 degrees (right) or -90 degrees (left)....but usually there isn't an option to make a slightly off-center from vertical strike - say, 10 degrees to the right.
The speed of the movement is usually similarly constrained - the strike occurs at a defined speed. There is, for example, no mechanism to start a strike quickly (as in a feint), hesitate or slow the movement, and then abruptly complete the strike. Such movement patterns are familiar to anyone with even modest ability in boxing, basketball, fencing, or many other sports. We have, as a matter of course, accepted that video game technology does not support these more complicated gestures. One reason is the classic controller - we press a button and the strike is made. In the small, the controller gesture is simple, discrete, and without subtleties such variance in speed - it is no surprise that the on-screen behaviors are the same.
Now, Nintendo puts the Wii in our hands and we behave differently. Part of the great fun with the Wii is all the dancing around and flailing of arms involved in using this controller. Sadly, for now, it seems that these movements are not represented on-screen with full fidelity. While the Wii translates my rotating arm movements into rotating arm movements on-screen.....it doesn't replicate the slight tilt in my body, or the exact speed of rotation, or that I am accelerating more in the back half of the rotation. Simple boxing gestures seem to work fine (left hand versus right hand, strike the head versus strike the body) but not feints or aiming for the jaw rather than the head as a whole.
It appears that for now, while the controller has changed, the underlying game mechanics (in most titles) has not. It seems that while the Wii gestures may occur with all the nuance of human movement, they are translated (for now) into the discrete equivalents of the button-mashing that has driven game mechanics for decades.
Two caveats though...... First, my experience with the Wii is limited. I've tried it for brief periods in stores but don't own one (yet). I've also studied very closely the large library of videos available of people using the Wii published by Nintendo. However, it is entirely possible that there are modes of using the Wii controller that aren't immediately obvious....ones that would convey movement in the more realistic fashions that one expects.
More importantly, I think these are very temporary limitations on the Wii because there is already established application of more subtle, analog, movement in video game technology. The Nintendo, Sony PlayStation and Microsoft XBox controllers have all long supported analog control sticks - these have made possible gentle, gradual, graceful movements horizontally on the virtual playing field (forward, backward, left, right, move obliquely, etc.).
To date, while the lower body glides more gracefully across the playing field, upper-body movement has remained choppy. However, with the Wii controller available, it seems only a very short matter of time before a game title distinguishes itself by using this device to give manual gestures in games more complexity and realism.