In case anyone else ordered Diablo III from DS and is wondering where it is, I called and was advised they have not received stock (as of about 1000 AWST Thursday).
As mentioned elsewhere DS online is not showing it available on PS4 or XB1.
Dick Smith online charge you for the full amount upfront on pre-ordered games so if you can't wait to see if it turns up and decide to buy elsewhere, don't forget to ring them to cancel your order and get a refund.
Update - just saw there was some discussion about this a few days ago here: https://www.ozbargain.com.au/node/156899?page=1#comment
Yeah, still waiting for mine… $55 delivered is good and all, but what's the point of pre-ordering if they can't meet demand.