I'd pay if the price was reasonable
I do UK<->OZ (East coast) at least once a year. I'd happily pay a premium for this, but the question would then be "how does the cost relate to Business Class?". If it's approaching Business Class cost, then there's no point, as it'd be better to just fly Business.
The current 14+-hour legs OZ<->Dubai are bad enough in cattle class, so I'd never even contemplate a single UK<->OZ hop without being able to lie down somehow (and no I can't afford Business).
Regarding the 380's: we will now explicitly only book flights on 380's, preferably Emirates. Have done 777's and they don't compare. So, in general, Emirates get our custom simply because they have 380's. I doubt we're the only ones with the same attitude, so I'd guess that aircraft make a lot of commercial sense for Emirates.