Aside from a mobile phone, there isn't anything I've waited longer for Apple to make.
The Mighty Mouse is a programmable 5 button mouse with a scroll ball instead of a scroll wheel. The ball allows for vertical and horizontal scrolling as well as clicking. The shell design is clean and distinctively Apple, with its cleanliness afforded by the fact that the left and right click buttons are touch sensitive and don't need moving parts and therefor seams.
$49 at Apple (apparently stocked and ready to ship)