I have contacted WD with regards to support with Leopard, and after a month they still have not replyed, however one other user managed to get a reply.
I use 2 WD My Book Pro's 500GB. One clones the other as I am a DJ and have an extensive music collection that I back up. At the moment both mine will power down on shut down, but the 'button' will still pulse every once in a while, but this is the same behaviour as Tiger.
I use WD Button Manager to shutdown the second drive, but at the moment the Button Manager software under Leopard doesn't work, as confirmed by the other user from WD directly.
They are currently 'working on' the update, so hopefully with this, we should be able to power down our drivers.
We hope !
: )
- Neil