The world's august body of visceral Airbus-haters (and some more considered souls) is already queuing up to dance on the grave of the A340. Four engines just aren't necessary, they say, we always told you so.
Well, unfortunately for Boeing's sales team, some very sophisticated airline purchasing execs were a long time learning how 'wrong' they were. While they were absorbing this apparently obvious point, Airbus was shifting just shy of 400 of the type and another 500 A330s. How many of the A330s would they have sold anyway - hard to tell, but a good deal fewer I think.
The -500 really has turned out to be a step too far, but the same doubts surround Boeing's investment in the ultra-long range niche - and if anything deserved to be called a 'niche' then this is it. For both of them, in the game they're in, it just comes with the territory.
Anyone who thinks the four-engined idea was misguided either didn't live through the ETOPS debates of the last decade or has a short memory. Airlines and their staff at that time were quite understandably ambivalent about the assurances of the ETOPS gurus. And that was for fear of ending up in the ocean - not the much greater risk of making an unscheduled visit to Siberia with 300 passengers in an aluminium tube.
The fact is that the ETOPS debate will never be settled. If just one aircraft is lost mid-ocean because of consecutive engine failures (or conceivably concurrent engine failures) then what will that do to the market? I don't know, but if and when Airbus ends A340 production I bet they'll keep the CADCAM files nice and safe somewhere. You know, just in case...