Markco of Just My Two Copper thinks he has found the best farming spot in World of Warcraft, killing Scions of Storm in Storm Peaks. He claims you can make 385 gold in half an hour there, from the eternal air and relics of ulduar you get from those mobs. Additional income if you are miner or engineer, or both.
I must say that I haven't even looked for farming spots yet, so I can't say how good that spot is from my own experience. So maybe you know more. Do you believe that this could be the best farming spot in WotLK? Or is farming lets say Wintergrasp when it belongs to your faction bringing even more? What's your favorite farming spot?