This was Boeing’s statement. Why do I not find it so credible? Two reasons.
Well we should all know both A and B can put out some great 'statements' - some with more flair for the absurd than others.
We also all probably know the old adage, 'liars figure and figures lie'.
One thing you may be leaving out of the fuel efficiency equations my good friend A42, are the new next-generation fuel saving engines and Boeing's 'fast' or super-critical low-drag wing design that is to be used on the improved jumbo.
Of course all of these figures are based on projections - even the launch airlines for the A380 don't have the any meaningful numbers on costs yet, so my original statement as put forth by Boeing is speculative I admit.
Personally, I would not care to be aboard anything so large as either the A380 superjumbo or the 748 'new jumbo ?' - who would want to be stuffed up with hoards of the general public (read your average group of morons) for hours on end back in cattle class - ok well perhaps a group of well-behaved Europeans might be tolerable...
A trip on the superjumbo would be fun however, just for the experience.