Blizzard took out any semblance of elemental crafting materials in this expansion and replaced them all with a single bind on pickup item that drops from practically everything. The idea is to force crafters to go out and kill monsters instead of just buying all the materials for their stuff. Some people are pretty bitter about needing to actually play their alts but I don't much care. What I actually care about is what I can use these things for.
The reason I'm so curious now is I can craft a pretty significant upgrade weapon for 5 SoHs. I've only gather 6.5 total (and spend one getting realm first blacksmithing) so that's a pretty significant number. But if there's not really anything important to spend them on I might as well go for it, right?
The first thing you can do with an SoH is buy crafting materials. Ore, leather, cloth, herbs... All stuff I could spend money on if I needed it. Maybe if I end up with infinite SoH I'll use this to convert them into cash but if this is the best option I will absolutely craft a blue weapon out of them now.
I can buy more blacksmithing recipes. Recipes for PvP gear which might sell well? Again, though, this is converting SoH into cash and I have more than enough cash. On the other hand there are also some ilvl 450 blue recipes that make tanking gear. None of the pieces have hit or expertise which might be a problem. And will also certainly all be replaced in short order since we need ilvl 463 for challenge modes.
I can use it as a reagent for crafting a bunch of different blacksmithing things. Again, I could sell this stuff for money but I could also build it now before it would hit the market and become available otherwise. 2 make a low level weapon. 5 make a ilvl 463 weapon. 8 make ilvl 476 gloves/chests (but also take a large number of living steel, the new alchemy cooldown). 2 make ilvl 496 gloves/chests (but also take a large number of items only obtained by DEing a raid weapon).
Honestly, I look at this list and it really seems like all SoHs are really good for in the long term is making money. In the short term I can give a small boost to a few tanking slots, a medium boost to my weapon, or track down a ton of living steel for a medium boost to my gloves or chest. I think for now making a better weapon for questing just makes sense. Time to spend the rest of my SoHs I guess!