I was journeying through icecrown hitting up the quests from the recalcitrant death knights and devout argent crusaders, when all of a sudden I espied a recipe drop from one of the mobs I demolished. The mob skeletal runesmith, had just dropped Enchant cloak - Superior Fire Resistance.
It was just the thing I was looking for, a handy cloak enchant in preparation for Sartharion 3 drakes. An extra 20 fire resist to a cloak slot that does not have much in the way of useful enchants is certainly a nice bonus. After wowheading it though, I realize that this discovery was more than just a PvE boost, but an opportunity to make a few hundred more gold before WoW enters 3.1 Ulduar.
Unlike other Bind on Pickup alchemy and leatherworking drops from the same mobs, this recipe can actually be traded and placed on the auction house, although if you have one in your inventory the recipe will not drop again for you. What you can do is to send the enchant recipe to an alt, who will then place it on the AH. It currently looks to go from 200-400 gold depending on market saturation.
This is one way to stock up on this enchant recipe for enchanters, which I believe will increase in importance during Ulduar. A cursory view of the bosses in ulduar shows us several bosses that would require elemental resistances:
Hodir's Frozen Blows, it does 40,000 raw frost damage that definitely requires frost resistance for mitigation. Tanks will certainly want to top up their slightly outdated ilvl 213 frost resist gear with extra frost resist enchants. The recipe can be obtained from the damned apothecarists.
Fire Resist is currently still useful for tanks doing Sartharion with 3 drakes, and might also come in play on the hard mode of Ignis the firestarter.
Nature Resist from the cult alchemist, might be useful on the freyja fight although I am still unclear as to whether nature resistance would be required.
Finally, Shadow resistance from the cultist shard watcher, would very probably in fights against bosses dishing out shadow damage, notably Yogg-Saron. Certain bosses from the ptr also appear to deal hefty amounts of shadow damage.
A few weeks after Ulduar is released, hard core raiders will be moving into more challenging modes of the encounters, and would start doing such specialised regearing and customization. This period of time would be ideal to liquidate the stock of Enchanting Recipes. At the very least, once would also be able to pick up fur lining or protection recipes if they were also leatherworkers or alchemists in addition to enchanting while farming for those recipes.