How about a tradeing post in every major city where you post tradeables for sale with a keyword search? You could even have a Canthan Barter Liason upgrade for guild halls.
How about making items like weapon mods and runes stackable in your bank? Strictly for pack-rats such as myself

How about improved bag space? Perhaps an upgrade to rune of holding to rune of hoarding?
How about the ability to have your mini pets follow you across zones so you just have to double click it one time then put it away in the bank.
And like the Armory suggestion, how about a guy that would maintain your pets for you while you are "away". So many pets...so little bank space.
I apologize if I stole someones idea or ideas that have been posted here before since some of them are way obvious needs. If you have any other ideas or would like to submit an improvement to one of mine by all means please do!

Bri