I have had the MyBook Live now for a week an have been watching the Load Cycle Count increase a lot.
(To get the data use the Dashboard under Support - Create & Save. In this zip-file have a look at smart_info.
Parameter #193 is Load Cycle Count.)
The disk has:
Power On Hours: 162
Load Cycle Count: 2816
This is 17 load/unload pr hour in average.
The datasheet for WD20EARS says 300.000 for this (yes I know about statistical data).
I have been watching on day to day and it is increasing equal over time.
Energy saver is set to 10 min. Twonky server is on. The device is used i a private home - no pc or other devices are used during night (10 h).