QF's routes are fatter than CO's.

Take LAX-SYD for example. There could be up to four (4) 747's in a day (~1,500 seats) on that route. 2-3 of these flights leave within a couple hours of each other. This is a perfect route for consolidation and/or expansion onto an A380. Right now if they want to add a flight, it's a whole 747. With the A380, they can yank a 747 and replace it with a 380 for a moderate expansion.

I can't think of a single CO int'l route with that kind of seat capacity. What does CO fly EWR-LGW? A 777 and a 757, with a bonus 757 a couple days a week (~600 seats)?