If you are properly into gaming (fps mainly, some fast paced rpg's) then you should stay well clear of wireless mice. The reason for this is that the wireless transmitter can only update mouse movements at 125hz, whereas most decent wired gaming mice (i.e. logitech mx518) can have the usb port overclocked to give a refresh rate as high as 1000hz. You might think that 125hz is by far enough but trust me as a serious fps gamer there is a HUGE amount of difference between the two and you'll notice the difference almost immediately. I would suggest looking at
http://www.esreality.com/?a=post&id=1265679 for a very comprehensive review of all gaming mice as of last christmas. There have been little to no advances over the last year so it should be up to date still. It might not be as balla as your $100 Logitech mx revolution mouse but the mx518 still > all other mice imo