I have learned recently that Apple has two magic devices, the Magic Mouse and the Magic Trackpad. I have learned at least some gestures on the trackpad on the laptop, but now that I have a desk, I got a wireless keyboard and a wireless mouse, the Magic Mouse.
The Magic Mouse may support all the same gestures as the Magic Trackpad, but it is vastly inferior. For one thing, it doesn't stay in the same place; this is my primary complaint with mice, and the reason that I've pretty much always used trackballs. It also isn't anywhere near as easy to do some of the gestures on the smaller, curved surface - try doing a two- or three-finger swipe toward the pinkie finger. The mouse is going to move, the trackpad isn't, at least not when on a computer and probably not the wireless unit.
In fact, as I type this, our office manager has handed me the trackpad, which I have configured (with the mouse) and I can definitely confirm that the two- and three-fingered gestures do not move the trackpad. I don't think the mouse supports the four fingered gestures, but I never tried and now that I've removed the mouse (with the mouse) and given it back, I'm not going to.
As a typist, I tend to want to stay on the keyboard, which is why I installed Dashkards as soon as I discovered it. I generally prefer not to go to the mouse or trackball or trackpad, but the Magic Trackpad is pretty damn cool.
Update, 9/19: I like the trackpad pretty well. It still shares a certain disadvantage with mice and other touch pads that track balls don't have: if I'm dragging too far, I can wind up getting to the edge of the pad. Not a huge problem, and I'm sure I could play with the sensitivity, but I do find trackballs to be easier in that respect. I don't think I'd give up the gestures at this point, though.