Jaba,
When airbus 1st mooted the A380 it was delayed in design commitment for several years, because Boeing threatened to bring out a new 747 design (what we now know as the 748) which would make airbuses financial commitment in a new design untenable. So airbus cooled on the mega bus idea. This cycle happened several times until airbus eventually bit the bullet and actually started building the 380. So the Johnny come lately boys at Boeing decided to go ahead with the 748 design to compete with the mega bus. So far Boeing has been a little under whelmed with response and sales for the 748.
Le Dugong planned to burn 201T fuel on the 1st LAX-MEL.
Savings over previous 744 service was about 80kg/pax fuel.
Multiply that by 400+ pax by 3 or 4 transpacific flights per day (as more dugongs arrive) times 365 days a year and you will no doubt see the potential increase in efficiency. As for the 748, I'm sure it will be a great leap forward, but where the bloody hell is it - only Boeing knows, and they could have built it 10 years ago but chose not to. Airbus beat them to the ULH/bigpella market.
ps. It (A380) flies beautifully