Outfitter addon
Outfitter allows you to create multiple outfits and equip them with a click of your mouse. You can layer outfits, create outfits optimized for a particular attribute (ie, fire resist or maximum defense), and have outfits which automatically equip based on events like mounting up, stealthing or changing stances and forms.
What's new in Outfitter addon
The biggest new thing is Special Occasion and Mix-n-Match categories are gone. The Special Occasion outfits are now regular outfits with preset scripts attached. There are presets for all of the old special occasion outfits as well as several other useful scripts. This makes it possible to remove or rename any outfit you wish as well as to customize the behavior any outfit. Outfitter addon 4 also fixes several features which were broken by the release of WoW 2.0.
Important information about upgrading to Outfitter addon
Upgrading to version 4 will upgrade your outfits to eliminate the old categories and convert them to the new system. Versions prior to 4 will not work properly with the updated outfit data. If you want to be able to revert to earlier versions while trying out version 4 you will need to backup your Outfitter data file before upgrading and then restore that file before downgrading. The file to save can be found at "World of Warcraft\WTF\Account\{login id)\(realm)\(character)\SavedVariables\Outfitter.lua"

Version 4.6.1 changes
* FEATURE: Item links in error and info messages are color-coded by item quality
* FEATURE: Equipment change errors can be disabled with '/outfitter errors off'
* BUGFIX: Corrected item level optimization to ignore ranged, tabard, shirt, ammo and off-hand slot
* BUGFIX: Item level optimization adjusts for item quality (greens are 26 levels lower, blues are 13)
* BUGFIX: Removed diagnostic message when building optimized outfits
Version 4.6 Changes
* FEATURE: Optimize an outfit for max item level
* FEATURE: Added "deposit/withdraw all other outfits to bank" to outfit menu
* FEATURE: Added Argent Tournament script for automatic lance management (English only for now, sorry)
* FEATURE: Added Spellcast script to equip/unequip on a specific spellcast
* FEATURE: Added Multiphase Survey script (Nagrand daily) to automatically manage the goggles
Version 4.5.4 Changes
* BUGFIX: Talent scripts no longer cause equip/unequip when zoning
* BUGFIX: Corrected error in Falling script
Version 4.5.3 Changes
- BUGFIX: Titan's Grip is re-checked on a spec change
Version 4.5.2 Changes
- FEATURE: Added Stormjewel support
- FEATURE: Added Primary Talents and Secondary Talents scripts (under General category)