Maximum CPU has published a review of Logitech's Cordless Desktop MX 5500 Revolution.

Bluetooth wireless mouse and keyboard combinations are becoming ever more popular for the average user primarily due to the lack of cords. However, due to the latency time required to transmit keystrokes and mouse movements/clicks these devices have been a tough sell for the hardcore or even casual gamer. There is also the worry about batteries running dry right in the middle of an important project with no replacements in sight.

Logitech Cordless Desktop MX 5500 Revolution Review