First of all let me say that I have no animosity towards FFXIV and I'm sure it will be a fantastic game. I personally will not be playing it, if only because MMOs have already taken up a large part of my life and after FFXI dies I down I want to kick the habit permanently. This is just something for you all to think about as the game comes closer to release:
Most of FFXI's players will cite the game's community as the reason they continue to come back to it. Unlike most MMORPGs, players of FFXI are nice, friendly, and willing to put the group's happiness before their own. There are exceptions of course, but the FFXI community remains the game's biggest selling point.
In those terms, FFXI is a very unique case. It isn't terribly old, but it did draw on a lot of teamwork elements from early MMORPGs and gradually managed to gather a lasting community that could survive in those conditions. Most online games feature everyone working for their own benefit, but any player who has made it far in FFXI knows that things flow the best when everyone looks out for each other above themselves. Now that XIV has been developed from the ground up in a post-World of Warcraft environment, I'm not sure if it has the potential to cultivate the same kind of community.
The developers have already stated that XIV will be, for lack of a better word, easier. While I welcome that from the standpoint of someone who doesn't have enough time to fully enjoy FFXI as it is, I'm not sure if the new game will be able to maintain the same kind of player-base that makes FFXI such a pleasure to be a part of, even if many of the players have migrated over from the older game. We must remember that the mindset of an FFXI player doesn't exactly come naturally; the game practically forces us to behave the way we do if we want to achieve anything. Without that reinforcement, I'm just not sure if XIV will be able to cultivate the same community that made its predecessor so famous.
tl;dr (If you must): I don't think XIV's community will be so great now that the game isn't harshly punishing people for being selfish loners like XI did. What do you think?