Would you really rather use the Magic Mouse over the trackpad?
I've spent a month with these,
and I found the Magic Mouse is great for scrolling (both vertical and horizontal), but it sucks for pointing and left clicking/right clicking (compared to any laser gaming mouse, say Logitech G9). It also sucks for long-term use (1+ hours) because you have to hover your fingers instead of letting your entire palm rest on the mouse. Anyway, those were my findings, so I'm just curious if you prefer the Magic Mouse over a trackpad. Personally, I'd use the latter over the former.