My tuppence worth; I actually think that the 747s days are over now that the 380 has raised the numbers/efficiency bar for ultra long haul.
The past few years have virtually proved that 2 engines are the future for long haul, certainly as far as the airlines are concerned. I believe that the 747 models no longer carry enough people to justify its four engines. The 777 and other airbus models fly just as far and carry only a few less passengers.
For the relevant (high-density) routes, the airlines will only now consider the 380, as the 747 is now no longer superior (in terms of numbers) enough to justify its engines and therefore cost.