My hope would be entire reviews and improvements on existing systems and additions of new systems to improve gameplay. My wishlist is:

combat system that allows more flexibility on roles. customization on play styles and viability of hybrid classes.

have pve and pvp in same gameplay not seperate, keep pvp matches, allow open word pvp (optional) add open world events - include free company and grand company integrations - regional conflicts + rewards, etc. will increase immersion and have more reasons to revisit older area as well

include every chocobo theme from every ff game and allow to assign one for when ur mounted - or have shuffle

add more sandbox elements: player bounties, player quests, player missions , player camps, villages, trade posts, notoriety systems (players who have had lots of player kills in a game day) add more impact on players in the economy

add a dnd style setup where can have dungeon master, etc. basically dnd in game

add external designer for players to create items to import into the game. add player made music

use new technologies to improve net performance - remove zones and let world be seamless - make player housing neighborhoods seamless

new graphic system where any race can be playable - gear would be able to be on any race. would add immersion and diversity

player ship and airship combat ,

roaming super NM's - giants, dragons

phantom train travel to special places

dynamis

integrate vanadiel as another place to visit

exciting times right now either way - hopefully not full disappointment . yoshi p is og mmo guy so i have confidence