What about the possibility of an A320/321 sized aircraft doing 7-14 hour flights? This 150-180 seater A32X-LR could be the ultimate hub-breaker, enabling point-point services on less dense routes. I am thinking (say) AMD/BLR/COK/CCU-LHR, UK-Middle East/Africa, Canada-India etc.
Narrowbody comfort etc is an issue, but if 757/321 tyope aircraft can go transatlantic then this shouldnt be a problem especially if the aircraft are more generously configured with say 34" in economy. The A321 should be able to carry 150 pax in a long haul configuration, while the A320 could carry 120 pax in such a config.
Airbus would have to work on increasing fuel capacity and improving fuel burn etc to push the range in the 12000 km range. Would the economics work out?
I think Airbus could consider this instead of further stretching the 321 like Boeing did with the 757-300.