I'm a bit suprised that nobody brought these up here yet, apparently - enchanting materials for the higher level enchants are dropping significiantly in 3.0.8.

From here:
And here's a blue quote indirectly confirming that these are intentional changes:

I still don't believe they're doing it (enchant mats) right.

When TBC first came out, it was pretty well balanced, cost was directly related to rarity. So what happened to Large Prismatics? Their source. The only items you get in end-game activities are uncommon and epic. Yet, all the end-game enchants required previously appropriate quantities of Large Prismatic Shards.

It's out of balance right now simply because of the number of heroics being run is creating a very large quantity of Shards with little use. Yes, they should be introduced into more recipes, but not in much quantity in the end-game recipes. If they require a number of Abyss Crystals, they shouldn't require more than 2-3 Dream Shards. Dream Shards should be used in the mid-range recipes (+8 stats, expertise, hit enchants, etc...) that fill in the exact areas that the people creating the Dream Shards will need them.

I also think the cut to Infinite Dust is just a bit too harsh. An ideal range, consistent with previous tiers would be 2-3g per dust. I'm pretty sure they'll be dropping to 2g not too long after the patch, and a month from now will be 1g50s, only not dropping lower because it will reach parity with vendoring the uncommon items instead.

While I agree the value of dust might value, I'm not as persuaded it's headed off a cliff. The enchants with lower dust requirements are simply not being done very much at all. What's sucking up dust is the sheer variety of attractive enchants on the -- quite frankly -- endless availability of gear worth enchanting.

I could counter-argue that by reducing the cost of the high-end enchants, there will be even more demand for dust than there has been. Demand for low- and mid-range enchants should continue unabated as alts and lesser guilds get geared in the coming months, not to mention the huge influx of enchanting demand for pvp/arena gear. In the meantime, high-end enchants that were not getting done at all, now will. And many of those require dust. The fact that they require less dust than before doesn't alter the fact they are likely to be performed much more often than they were before.

Mount change = good

Inscription change = wait, I can now use all that Ink of the Sea? From a scribe's perspective, this will help immensely both for on-deman glyphing and stocking on cooldown materials. Not to mention Darkmoon cards.

As for enchanting, it looks like the Law of Unintended Consequences / Murphey's Law will be striking something fierce. While overall the change is good, the actual impact on the economy is rather up in the air. I've literally been throwing dream shards at my enchanter friend as a bonus for DEing things to dust/essences for me, because I didn't need them for meaningful enchants. Now it looks like the value of those dream shards WILL go up, but the impact on dust costs looks to currently be 'no change or actually an increase' as opposed to a drop. From a tailoring perspective, this is rather annoying from the PoV of accquiring dust for Imbued Frostweave. From a gearing up perspective, this is similarly annoying since dust will probably be just as limiting as dream shards will become at this point...and we're still gated by Abyss crystals. I suppose we're going to have to go with the unfortunately standard 'wait and see' until the devs take a second look at it...

So glad they're changing the enchanting materials, although I can just about keep up with the essences I need i've got 60 dream shards sat in a bank doing nothing and about 30 stacks of dust which aren't getting used either!

Incase anyone was wondering, this is from making JC rings and random tailoring/blacksmithing items to DE

...You should transfer to Moonguard and donate all that dust to me *nods faux-sagely*

Seriously, if you have that much dust 'doing nothing', you are LITERALLY sitting on a gold-mine by means of the AH. Before the announced turn-in change for Inscription, this was my recourse for excess Ink of the Sea, and pretty much paid for the herbs needed to get the cooldown materials I need[ed] with self and friend glyphs being incidentally a bonus. Enchanting should be EASY to turn around a profit on, literally everyone wants the mats with dust rating high.

I've stuck some on the AH to see if they will sell, hopefully people find them amoungst the bunch of clowns with 100 1 dust auctions (can you filter by quantity?)

No, but people will definitely find your stacks of 20. I've sold dozens and dozens of stacks of dust. There's also like two pages of 1 dusts up but people will scroll by them to get the full stacks with no problem.

There are plenty of popular addons that will allow you to sort by "price per unit", so if your stack of 20 has a lesser price per dust than the hundreds of single-dust-auctions, yours will sell (while the profit might over time be smaller, it has the added advantage of next to no "auction expired" mails)

managed to shift some stacks whilst I was out visiting relies, going to put a few more on for slightly higher price and keep the rest for making bags