747FOCAL
I just hope that Boeing learn their lesson. I read somewhere that when they were looking at the 747-400XQLR(?) they reckoned that a number of aerodynamic improving and noise reducing mods that were supposed to be part of the XQLR would be retrofittable to the -400 i.e. blunt-edged (MD11 style) flaps, chevronned nacelles etc so that existing aircraft could meet QC2 and reduce fuel burn etc. If they decide not to do this I hope someone else does - maybe one of the outfits you mention - because with 600+ aircraft out there with no obvious replacement there would be a significant market for a package of mods (maybe including the blended winglets) which resulted in reduced noise, costs and improved performance.