I think this mouse is aimed largly at PC users, and with the switch to Intel next year along with an new update to the OS (if they can improve on an already perfect operating system) it will be very useful in tempting PC users over to Mac OSX.
As a long diehard PC users i used to come out with the same arguments relating to the mouse, i hated OS9 with a passion and i didd't expect Mac to really be around now. Bt things change, and since working in design i have stated to use the mouse less and less, relying on Hot-keys and actions within Adobe and the OSX tiger operating system itself.
The thing i missed the most was the scroll wheal, and its a great additin to the Mac mouse, i will still wait a little longer for the wireless version, as i'm in no hurry to update.
BTW i have moved from PC to Mac and i now have a new iMac, my advice is get one, it is way better the its hype, and has endless possibilites, and if you can wait untill next year it will be cheaper! I just love the way that everything synchronizes together, it really helps you to organize.