I think SE has in the pipes already a fix that will allow players access to abyssea from the 3 main cities and linked Auction Houses to help remove the congestion in port jeuno but i really feel this will only remove a minimal amount of stress that this zone is seeing as it will still be the main zone to see shouts and as such the main zone to create pick up parties.
What I feel will certainly remove the stress from port Jeuno and will also make forming pick up groups so much faster is a server wide shout channel that can only be used once every 3 minutes and only after level 30 for the use of creating pick up parties. SE could make it as simple as just an ability that every job learns at level 30. If this is implemented along with linking the AHs and also adding abyssea teleport access in the 3 main cities i would be more then happy to spend my time sitting in Bastok, my home nation, rather then Jeuno or Whitegate. I feel this is something SE should really look into and at this point in the game i feel the players base and the game its self is ready for this change to take place in order to better the productivity of FFXI as a whole and in no way would hinder or break anything in existence at this current time.
So please SE, PS2 limitations permitting, consider this as an option for the better of FFXI as a whole.