I'm sure this has been said many times, but I'm doing starting a new thread anyway.
Mobile Apps please--- Android and iO6. I'd love to be able to send my companions out while I'm at work or on the road just to get them farming materials for me.
GTN app where I can put stuff up, browse and buy from my phone. You can make it mandatory to have the security code on the account or what not, but it's doable.
Or at the very least, a browser interface where I can do this without logging into the game client.
My other suggestion which I'm sure has been noted is the ability to see people's name in chat/guild/wherever by Legacy surnames only. It keeps it easy for the alt hoppers or people who choose not to display their legacy name because they love to troll around.