Well... hmm what I would like to see....
Dragons: I do really like dragons... Wyrms or whatever.. some type of flying bad ass creatures.
Mini games: A great mini game is Blitzball. I think we should be able to recruit NPCs and expand on that idea. A guild could have a football, baseball, basketball, and hockey team.
Airships: I think this could be added as well and it would not compromise PS.
Hmm what else,
A real class system: I like being able to choose a general class... like Red Mage, Blue Mage and the like... I know we have some but I would like to be able to choose a class then be able to modify it a little.
NPC Mercs: These can be partners for hire. They can help you power up.. like in Diablo II and many other games.
The ability to be able to apply real battle tactics would be nice also.
I will have more soon