The most comprehensive list that I currently know of is Wowhead's, dating from July.
Mounts:
- Ashes of Al'ar: Kael'thas Sunstrider, Tempest Keep
- Deathcharger's Reins: Lord Aurius Rivendare, Stratholme
- Flametalon of Alysrazor: Alysrazor, Firelands
- Smoldering Egg of Millagazor: Ragnaros, Firelands
- Swift White Hawkstrider: Kael'thas Sunstrider, Magister's Terrace
- Reins of the Blazing Drake: Deathwing, Dragon Soul
- Reins of the Blue Proto-Drake: Skadi the Ruthless, Utgarde Pinnacle
- Reins of the Green Proto-Drake: Cracked Egg, Oracle dailies
- Reins of the Drake of the North Wind: Altairus, Vortex Pinnacle
- Reins of the Onyxian Drake: Onyxia
- Reins of the Drake of the South Wind: Heart of Wind, Throne of the Four Winds
- Reins of the Vitreous Stone Drake: Slabhide, Stonecore
- Reins of the White Polar Bear: Hyldnir Spoils
Pets:
- Sen'jin Fetish
- Tirisfal Batling
- Shimmering Wyrmling
- Mulgore Hatchling
- Durotar Scorpion
- Enchanted Broom
- Teldrassil Sproutling
- Dun Morogh Cub
- Mechanopeep
- Ammen Vale Lashling
- Cat Carrier (Bombay)
- Proto-Drake Whelp
- Tiny Sporebat
- Cat Carrier (Black Tabby)
- Captured Firefly
- Giant Sewer Rat
- Obsidian Hatchling
- Dark Whelpling
- Cat Carrier (Siamese)
- Parrot Cage (Green Wing Macaw)
- Gundrak Hatchling
TCG Loot:
- Imp in a Ball
- Dragon Kite
- Fishing Chair
- Paper Flying Machine Kit
- Goblin Gumbo Kettle
- Hippogryph Hatchling
- Picnic Basket
- Tabard of Flame
- Goblin Weather Machine - Prototype 01-B
- Banana Charm
- X-51 Nether-Rocket X-TREME
- Riding Turtle
There's also non-cosmetic gear like the once-removed T3 set, heroic-level gear and Mists profession recipes.
