Please can you tell us what aircraft are to be used in 5-10 years on those routes that have become “doable” because of the A330/A340/777?

For the growing A330 routes an airline would rather prefer to upsize to a A350-900 or a 787-10 if it wants more capacity (something like a 25% increase in PAX with added range) . If the airline wants to further upsize then it can go for the A350-1000 which adds another 20% or near abouts . An airline can also increase frequency .

For The airlines that operate the 777 family they can upsize to the bigger 777 varients and add more freq with them ( Like BA is doing with its LHR-JFK route) , when you have 250 seater 787-8 being used for 7000nm flights you have more options then just increase capacity per jet per route , you have greater options with frequency.

Or perhaps you are anticipating zero growth and/or a sudden desire to not go down the “green” route and start added runways at all airports?

There wont be zero growth infact new pairs and routes would be made possible with aircrafts such as the 787 and A350 due to their potent RASM-CASM , airlines that have embraced the A330/340,777 families and these families have sold close to 2000 jets (1800 some) have shown that if smaller aircrafts can compete (I use compete and not better) on CASM as compared to bigger aircrafts then they would rather prefer the smaller aircrafts on accounts of better RASM , flexibility and lesser risk . The 777300ER and its equivilant A340 varients are a perfect example , although they dont beat the 744 interms of CASM however they come very close thereby being prefered by airlines on accounts of better RASM , lesser risk etc etc , the new A350-1000 will be another banging aircraft it would most likely be very competitive with the A380-8 and the 748 interms of CASM and thereby cause a lot of the airlines to think about using it due to the better RASM it generates for them , moreover we still have to look out for the post 2015-2020 timeframe where technology can advance even farther.

The 748 and A380-8 wont be the CASM leaders for long , infact i see the A350-1000 being very CASM competitive against both these aircrafts ( i use the word competitive and not better) , however the A380 has an advantage of being the smallest aircaft of its designed family , the A380-9 (if ever build) will be the King of CASM as they say , however there would only be a no. of routes where it would be able to provide good RASM to justify stuffing in 700 or so PAX .

The problem for the A380-900 is going to arise if boeing decides to pursue the Y3 which would be (if ever happens) in the 2015-2020 timeframe , a 350-450 seater (effective seats and not like the 77W which stufs PAX in) twin would be very CASM competitive speacially if it is a second generation CFRP fues,wing etc etc .