Didn't see anyone talking about this. But its great news that they want to give us at least one more retainer if I read this answer right:

Q16: The amount of items will increase, but I’m having inventory problems with my current items. Will you be doing anything about the amount of inventory space?

A16: The additional retainer service couldn't make it in time for patch 2.1, so we will be increasing the amount of items that can be stored in the Armoire.

Too bad it didn't make it for 2.1

I wouldn't mind if the third retainer only stored items and you couldn't use it to sell stuff. I wish all untradable and non-convertible items could be stored in the Armoire.