Bags (netherweave, herb, mining, soulshard).
Buying eternal fire, selling crystallized fire at 200% price.
Disenchanting JC rings.
Buying greens, selling disenchanted materials.
Buying borean leather, selling heavy borean leather (even leather scrabs -> light leather is very profitable).
Buying mats for preTBC enchants, selling scrolls of said enchants (+4 stats/100 health will be huge sellers in 3.2!).