To me personally, WoW caters more for the casual player. The one without alot of time to do things.
In FFXI you do things more in a group than with yourself. In WoW i heard ppl not really wanting to party up to do quests cuz they are too into doing their own quest. While in FFXI getting a group to do major quests is a requirement. While you can say FFXI quests are not rewarding, you can say the same to WoW a few years down the road when Gold and Silver money in it starts to inflate (unless they get a good money sinker ppl like). 3000 Gil was once alot too, and that is the same thing for WoW IMO.
Crafting also seems easier in respect to FFXI, as Suzu said if its that easy to fish, the 0.1 skillup in fishing obviously means alot less than the 0.1 fishing up in FFXI. Therefore if the entire road of fishing is that easy, its just that much sooner to end fishing before it becomes boring. Dont know, but IMO, if its that easy to skill somthing up(IF), then its not much of a reward saying i have a lvl 50 fishing skill in WoW, than a lvl 50 fishing skill in FFXI.
Crafting seems to be more profitable at start, but i think reason is that everyone is reletively low lvl for the most part. I mean i bet at one time Lizard Jerkin sold for quite a good sum of money until more crafters can create them too. Same for WoW i feel.
PvP i heard its real good, but i dont feel it should be that central to MMOs, but depends, look at Lineage 2. FF has a more co-op Gung Ho feeling no matter what nation, while in WoW...OMG YOU ARE THE HORDE! DIEE!!!!! *stabbity* o.o Also since you can solo most of the things, meeting other people would be that much harder. However that does save time and the frustration of parties and alliances sometimes. I however like to party, and its one of the things i enjoy FFXI more than some game like Ragnarok Online where i can solo the entire way to lvl 99.
Final Word? I wouldnt get WoW just yet, its too early in its lifespan before you can say much about it. Just like FFXI and RO before it, the start is always the best feeling and all. When you pay per month, you go for longetivity. Its too early to make a judgement on WoW especially compared to FFXI where they got a 2 year headstart and alot of things already figured out(after all, in FFXI beta we thought 4 WHM parties are the best :P and good ol RDM/MNK and 5 WAR 1 WHM PTs). Give it at least a year or two, then we can see accurately how things end up. SWG was good in the beginning too, remember that :P