At the end of the day the 380 right now carries basically the same amount of payload as a 300ER. The early 15 380 only earned their stay because EK only paid about M$85 for it (List price ~M$300). That's a lot of gas to squander...
Of course that will improve with future versions, but not by more than 10 or 15 tons of payload per airplane.
My guess is that they use the next 40 or so 380's as a bargaining chip to get more destinations in germany and other parts of europe. If they don't get them they'll cancel 380's and 350's as needed and kill Lufthansa and Air France with 777XR's (Or whatever they'll be called).
I don't think EK will ever have more than 50 380's in service.