Here are all the stuff you might want to farm for to make a bit of gold from those new 2.3 recipes Recipes - Items - World of Warcraft.
While I am not sure which ones will become a successul seller, I would imagine the really hard to get/make mats will do prett well.
Alchemy:
· Elixir of Major Strength
· Primal Might
· Skyfire Diamond
Elemental:
· Primal Air
· Primal Earth
· Primal Fire
Enchanting:
· Arcane Dust
· Greater Planar Essence
· Large Prismatic Shard
· Void Crystal
Engineering:
· Felsteel Stabilizer
· Khorium Power Core
Food:
· Clefthoof Meat
· Lightning Eel
· Small Egg
· Talbuk Venison
Herbalism:
· Felweed
· Mageroyal
· Mountain Silversage
· Ragveil
Mining:
· Adamantite Ore/Bars
· Eternium Ore/Bars
· Fel Iron Ore/Bars
· Felsteel Bars
· Khorium Ore/Bars
Reputation Items:
· Arakkoa Feather
· Bog Lord Tendril
· Coilfang Armaments
· Fertile Spores
· Glowcap
· Mature Spore Sac
· Sanguine Hibiscus
· Unidentified Plant Parts
Skinning:
· Fel Hide
· Knothide Leather
· Nether Dragonscales
· Thick Clefthoof Leather
· Wind Scales
Misc:
· Light Feather