20 Years, maybe we'll be talking scram jets and 2/3 hrs London/Sydney then maybe no Singas stopover (another 2/3 hrs on ground) as there will be another launch and landing, a lot more expensive fuel used for a 20 min?? flight. But I'm sure there will be direct flights of some sort to Singas, BKK , KL as these will always be wanted destinations. In fact there would be weekend shopping trips, no more 24 hrs travelling.
My opinions only.