My biggest peeve at the moment, is the fact you can not sort your inventory, manually, or automatically.
I was just wondering whether there's been any information in regards to this, as it is quite simply the thing most annoying thing at the moment for me. I even went and inventory danced with my Retainer just to make it just a little organized.
Oh, also one thing I noticed... There's absolutely no way to send items to your other characters, without utilizing a middle man, which is... annoying.