I've been playing Demon's Souls on the PS3 -- solid game, but one of the things that's impressed me most is its subtle, innovative online elements.
One of these is the "message" system. See, Demon's Souls is single player, but as you make your way through the world you have the opportunity at any time to scrawl a message on the ground. It might be something like "The next enemy's weakness is fire," "Watch out for a trap ahead," or "Secret passageway." The messages are sent through the network so that they appear in the games of other players in the same area.
It seems to me that this would be perfect for an MMO, and especially one from the FFXI team. We all know about "So chilly" syndrome: their love for providing the least amount of information to the player as possible. That's not likely to change in XIV.
I think their purpose in making the game this way is to encourage players to work together and share information on how to complete quests. And we do, but the huge flaw in the system is that we have to go outside the game to do it. You're not likely to find the precise kind of help you need by asking a random person you meet in the game. So we go to websites, which is a chore and which breaks immersion.
An in-game hint system run by the players would solve a huge part of this problem. It's natural and completely authentic to the game world -- in a land packed with adventurers, why wouldn't some of them leave notes to guide later travelers? It wouldn't be as good as a detailed strategy guide, but it would probably be just enough to let players get through most quests or missions without checking outside the game. It would keep some of the sense of adventure and discovery alive as you discover each clue along the way.
The other nice thing about the system is that it can be controlled and balanced by the developers. In Demon's Souls, messages are constructed from a list of preselected terms and phrases, similar to the auto-translator. This method could reduce spam, prevent the messages from giving too much away, and be automatically translated into all of the game's languages. Demon's Souls also includes a "recommendation" system so that the best messages can be voted up. A game as big as XIV would probably need something a little more complex (like a vote down option to eliminate useless or obsolete messages) but the principle seems sound.