Can't see an quad with reduced cargo space, lower MTOW, reduced passenger space, and range making it into service unless Boeing pretty much give it away.
The new engines are all well and good but so long as the 380 gets them I doubt Ek will be interested, the 777/380 fleet mix wouldn't leave much space for a748...I would be interested to see the fuel burn per passenger when compared with that of a current-generation 380 on identical sectors as well, I doubt anyone actually knows. Fuel tanks are smaller, but they'd have to be to carry what 50 odd fewer pax.
LH may well be happy with their 748's, but it may fit their business model - the operation is entirely different to Ek, it also still decides to fly the 346 LH and makes rather less profit each year (that's another thread though).
So long as the marketing keeps it up, I know of plenty of people who prefer the 380's premium cabin when travelling any reasonable distance (me included, hate that middle seat in business), and while it may not work in most of the West, in other parts of the world people don't just want the cheapest price, they want to rub their mate's face in the fact they flew an EK 380 when they went on holiday, as ridiculous as that should be.