Not sure if anyone's wrote about this yet but couldn't find it on the front page so here we go -
FFXI's inventory system sucks worse than a 90yr old hooker with lung disease. It's small, hard to view, impossible to sort and has an inexplicable automatic item queue for anything that you can't fit in there. In short, it's crap.
Having a better inventory system is going to be one of the most important factors in me buying XIV, I seriously can't imagine anyone actually liking the one in XI much, so what do you people think should be done about it in XIV? A bags system like WoW? Or maybe a weight-based system like in Rappelz?
Personally I think the gobbie bags quests and having a fixed inventory size based on that was fine in itself, but it could do with a slot-based rather than list-based interface, and allow drag-and-dropping. Also I'd like to see dead enemies as containers rather than just dying and automatically transferring useless items to you regardless of whether you want them or not. And of course, more space earlier on in the game.
Another thing that confounded the low inventory space to start out with was the fact that equipping armour/weapons didn't remove them from your inventory slots. Obviously with only 30 slots initially, and most of that still being took up by your equips, lower levels were pretty much screwed for any extended farming trips. The only problem in the old system I'd see with implementing this is of course the dreaded de-level where you lose the ability to wear your current gear, but if SE leave in de-levelling there's obviously a few workarounds to this like just keeping the gear on and losing it's abilities.
Finally on the moghouse side I think it'd be cool to see some kind of armory. The one main problem with the jobs system for inventory was multiple classes needing multiple equipment sets and effectively storing them. I think it'd be nice to see some kind of system to store equipment sets, maybe dummies you could equip like a normal character and use one button to swap all the gear off. You could buy specific class ones or maybe just have generic ones. They'd look pretty cool in your house too (assuming you have a house in this game).