Yes, as Flykal mentioned, they do sell ALL
seats, with different prices for the seats depending on where they are located in the aircraft.
Seemed that the window seats either side of the plane behind the wings are the most expensive, followed by the "other" window seats, then the "window side aisle seats" and finally the middle row seats going for the cheapest. And of course I'm only talking about economy class seats - first and/or business class are different prices I think. And yes for those window seats it seems they do have a system in place whereby they get the passengers to swap seats halfway thru thre flight, which is about the point where the aircraft turn-back somewhere in Antartica.
I think QF
is still offering theese flights this southern summer (Dec 03/Jan-Feb 04), and there seems to be a website somewhere about it, but I can remember the URL. Perhaps someone else could help.