Congratulations Sheila!
I had the opportunity to buy a 5D last month for about the same price as advertised by D-D, but it was Canon Australia stock with local warranty/etc. Unfortunately I didn't have that sort of cash lying around, but it was very tempting.
It was stock that had been "overdelivered" to a camera store (run by someone I know) and they were willing to sell it for cost price. But I know they don't have the camera any more, so the question is whether you can find another store willing to sell at no profit.
Onyx's advice is probably the best, given your requirement for Canon Australia stock. But given the above information about the price that Canon Australia charges dealers, you're unlikely to match D-D's price.
Incidentally, when I bought my 20D I didn't get onto the waiting lists quickly enough and spent months languishing on hold waiting for stock to arrive (my D30 and 10D had each been in the first batches to arrive in the country). In the end I gave up and bought one from Adorama in NY (I had it the next week, and with the grip for the same price I would have paid for just the body locally). The point of this story is that I had some repairs done under warranty by Canon Australia with no questions asked. Having a proper receipt and not mentioning that it was from an overseas merchant may have been the key, but I don't know.
Drifter, all the people I personally know with a 5D are very happy with them, and from the couple of times I've used one I know I'd be very happy with it too. It's not just the size of the sensor: the advances in the camera itself over the 20D all add up.