The economics of ultra long haul flying go down since you have to carry a lot of extra fuel in order to carry extra fuel... which means that weight increases just to carry the extra fuel that is necessary to stay aloft longer.
I would be surprised if any airline ever adds flights from any point further east in the US than DFW. Clearly the reason that route works is because of the AA hub and the AA/QF joint venture.
It is doubtful that the value is there to operate a flight much longer than DFW-SYD.
Meto can respond but there are also limits in terms of crew duty and rest time. I'm not sure how much more window DL has in its pilot contract to add flights that are any longer than ATL-JNB but that flight is one of the longest in the world and the longest by a US carrier, IIRC. JFK and MIA to JNB might be shorter nonstop but DL has the ATL hub as an advantage and JNB's altitude at about 6000 feet means there are very few aircraft that can operate from the US to JNB nonstop year round.
Agreed. Unless fuel prices decline (or moderate their increases), I predict that the future will hold more new shorter international flights than new ultra-longhaul flights. Consistent with that is the smart (IMO) buildup of SEA by DL into a bigger international gateway.
Sure, there are some high-fare paying business travelers who value nonstops and don't really want to connect, but the reality is that there aren't very many of those travelers. It's got good location.
I don't think that ANC will return to its former glory where every flight to Asia will stop, but I don't see ATL, IAH, DFW or MIA getting as many new long-haul flights to Asia as perhaps SEA, YVR, SFO and LAX.
Similarly, I don't predict very many new European flights from SFO, LAX or SAN for the same reasons. Even if AA manages to get the LAX-GRU frequencies, that's a very long flight and in the past, MAH4546 has said that LAX yields to Brazil aren't very high. Lotsa demand but not high yield demand. That doesn't bode well for the success of that flight (if it ever happens).