From MMOChamp, which is quoting an article where Tom Chilton(Kalgan) answers a few questions.
Quote:
•The Transmogrifier NPC, which will let you change the appearance of any armor piece on you, while retaining the stats of your current gear. (= T12 stats, but with the Tier 2 look!)
•Players won't be able to change the appearance of their armor into another armor type or class armor set, and you might have to own the armor before you can use it to swap the appearance of your existing armor.
•The Void Storage is a new type of bank where players will be able to store their old armors in order to free up space in their regular bank.
I'm sure it will be limited to raid teir gear, but damn it would be awesome if I could wear what looks like a bunch of RP looking greys into a raid, haha. Also, this means I have to decide what looks best of my characters for a raid situation!
It's too bad weapons and shields weren't mentioned. Though I understand why. If shields could be changed, Gohir would be insisting even more on Black Temple runs, heh.