This will depend upon whether the dishwasher is fixed permanently to the house or is something which is able to be moved around the house with minimal effort. Under the standard REIQ contract, all objects fixed to the house stay with the house unless specifically stated otherwise in the contract.
The majority of dishwashers today are built into the kitchen in that there is a specific spot in the kitchen underneath the bench where the dishwasher sits. The dishwasher is then connected to the plumbing with the intention that it does not move. The court has ruled that in this situation, the dishwasher stays with the house.
In some of the older houses, the dishwasher is on wheels and is connected up to the taps or otherwise moved out of the way when not in operation. You would be able to take this dishwasher with you. Of course, if you are in any doubt your or your real estate agent should specify what happens to the dishwasher in the contract.