"finally..."4.0 starson by urpwnd
Pros: bluetooth, laser mouse, multiple buttons, only *requires* one battery (but can use 2)
Cons: side buttons still share function and are somewhat hard to press, tad expensive.
Summary: overall, this seems to be an awesome mouse so far (had it for a few hours now). it improves upon the previous mighty mouse by implementing bluetooth for the wireless, and a laser-based sensor (compared to the previous optical one in the wired mighty mouse). you can run it off one battery (to save weight) or two to have the runtime as long as possible. it's simple to turn on and off by merely sliding the laser sensor cover, and even with two batteries in it, is quite lightweight. it tracks well and slides smoothly on any reasonable surface as well. it is a bit expensive though, at US$69. however, compared to other bluetooth mice, i think it's a reasonable amount for a first-party peripheral.