The "quarter pound" referred to in the burger is actually the uncooked weight of the meat. By the time it gets cooked it actually weighs less than that.
Aside from the marketing side of it (more people will know what a double Quarter Pounder is by the name, rather than a "new" product called the half pounder, as shown by the dumbarse that served Swifty at the drive-thru), I can only assume that they chose to call it a double Quarter Pounder because the Quarter Pound of meat was already an established measurement, and they are just doubling it.
Xcidium, in reference to States and Territories:
The states originated as separate British colonies prior to Federation (in 1901). Their powers are protected by the Australian constitution, and Commonwealth legislation only applies to the states where permitted by the constitution. The territories, by contrast, are from a constitutional perspective directly subject to the Commonwealth government. The Australian Parliament has powers to legislate in the territories that it does not possess in the states.
Most of the territories are directly administered by the Commonwealth government, while three (the Northern Territory, the Australian Capital Territory and Norfolk Island) administer themselves. In the self-governing territories the Australian Parliament retains the full power to legislate, and can override laws made by the territorial institutions, which it has done on rare occasion. For the purposes of Australian (and joint Australia-New Zealand) intergovernmental bodies, the Northern Territory and the Australian Capital Territory are treated as a state.
Taken from
Here
Interestingly, there have been several relatively recent attempts by various political groups to redefine the Northern Territory as a state. Every time this has gone to a refferendum the voting population of NT has overwhelmingly voted to stay a Territory.