I think another reason I’m enjoying the Magic Trackpad is because it doesn’t require my hand to move very far to get to it. I’m a keyboard guy — if it can be done with a keyboard instead of a mouse, I use a keyboard. Always. Having the trackpad so close to the keyboard in my case, just a few inches to the right of it; much closer than my mouse makes it feel more like an extension of the keyboard, and less like a separate device.
Just got back from the Apple store where I tried to pick one up for myself – none in stock. I hope to get one next week, from toting around with it in the store I can see how appealing it is.