Update - Added a list of the keys staying in-game.
Patch 4.2: We Bid Thy Keyring Adieu
UpdateWorld of Warcraft has evolved quite a bit since the day the Keyring bag slot was added in patch 1.11. When implemented, this Keyring provided players with a convenient way of storing dungeon, quest, and other keys automatically. Back when the largest bag was a mind bottling 18 slots - rumoured to be bottomless - the Keyring helped save precious bag space. But as things tend to do, time went on, bags got bigger, and designs for gating content (literally and figuratively) evolved through the years.
In today’s Azeroth, keys don’t really serve much of a purpose except to take up physical storage space from the game (which could be used for other awesome stuff), and visual interface space on yours. Because of this, we’ve decided to get rid of the Keyring in order to free up some user interface space for exciting new features. This change could also potentially allow us to play around with the amount of default storage space you’re allotted down the road. So, what does this mean for you and the keys you might not have looked at in the last couple expansions or so?
We’re currently working on the implementation of a system in patch 4.2 which will handle the removal of the Keyring, while causing you as little hassle with keys as possible. Some keys which no longer serve a purpose in the game will automatically be removed from your inventory. In return, you’ll be compensated for them with their respective vendor sell prices in gold. You might also have random leftover quest keys from outdated quests, or quests which were removed in Cataclysm. Keys that fall into this category have no use and no sell price, as they are labelled as quest items, and will be automatically removed from your inventory. Any remaining keys that might still potentially serve some use in the game will be transferred into your regular inventory. If there is not enough space in your inventory to hold any leftover keys once patch 4.2 hits live realms, the keys will be placed in a backlogged storage system. Once space is made for a backlogged key, the key will take that space after you log out or switch to a new zone (i.e. changing continents, entering a dungeon or Battleground, etc.).
We are continuing to work on new ways of allowing you to better manage the storage of various items in the game, and it is our goal to make sure the removal of the Keyring causes as little inconvenience to you as possible.
So, just as a reference here are the keys we're currently seeing as ones that will not be converted to gold or removed upon release of the patch -- if you have them they'd be put back into your normal inventory. This isn't necessarily a final list, and it's possible we could cut the list down even further before 4.2 releases.