The first is Vaultkeeper Razhid, who carries the title of 'Void Storage'. I think this will finally be a player owned bank that is shared across all characters on the account, which would finally allow you to move items across different realms without the need to transfer an entire character. As someone who absolutely loves leveling alt's, this news is great, simply because maybe, just maybe, I will get around to rolling an Alliance toon to 85 (I said maybe! My heart will always align with the Horde!)
The next is Warpweaver Hashom, who is a 'Transmogrifier'. This one is a little harder for me to pin down with theory, but I have three good ideas as to what it might be. But lets start off simpler than that. Google states that the definition of Transmogrify (which we can assume that Transmogrifier is derived from), is "Transform, esp. in a surprising or magical manner". So that gives me a few ideas.
The first, is that he will be able to allow all characters to be recustomized in a similar fashion to the barbershop, but with their appearance. As it stands, Tauren are the only race that can change their skin color once they are created, and even then it is only for Druids. This would (hopefully) also come with new models for the old races (orcs, humans, etc.).
The second, would be for a way to 'dye' your items, although I am not sure this goes with Blizzard's design philosophy for their current items. Most items are recolored versions of different armor. This one is pretty unlikely I believe.
The third idea I have is very very out there, but hear me out. He allows you to assume the form of the opposing faction for the purpose of Real ID grouping.
Now, I am not sure at all if these are real features going into the game, at this point this is just theory and guessing. As for the bad news about this stuff? If I am right on the Void Storage and the Real ID grouping, I feel this would be a part of the planned 'premium' accounts Blizzard wants to initiate, meaning it would cost a few bucks extra to access these features.