Here's one from Verimonde on the beta forums:
Sharpening Stones and also Wizard Oils have been discontinued. While they were something nice to use once in a while for most people for many raid guilds they were simply another burden to the cost of raiding. They also caused some issues in that they only helped certain classes and took away some of the uniqueness of other classes who were able to imbue their weapons with temporary enchants such as rogues and warlocks.
It would seem that the old oils and stones won't be removed from the game, but Blizzard are not introducing any new ones after level 70. But, just as many of us farmed for the level 60 Brilliant oils from ZG rep (because they were so good), this new announcement immediately had people assuming that we would all just have to farm for Level 10 oils to put on our Level 80 weapons. That would be tiresome to say the least.
Sekdar from the beta server Northrend revealed that old oils and stones will NOT be able to be applied to high level items:
Image 1: Applying a stone
Image 2: Failed!
Which means that we won't be forced to go farm for Outland materials to maximise our stats in raids.
It's all very interesting. I think the references to rogues and warlocks is a little weak, and really the main reason would be economic, not for reasons of keeping rogue poisons a unique feature of the class.
Personally, I don't see how 3 Arcane Dust (that we are all swimming in at the moment anyway) and 1 Nightmare Vine (even as one of the most expensive herbs) was terribly burdensome - and I would imagine that Northrend mats wouldn't be too different. Even when these Outland mats were at their most expensive on my server, this would have equated to about 6g per oil, and with 5 charges each that last for an hour, that's 1.2g per hour or for most people who raid 4 hours per night - under 5g for an evening of raiding. That's really not expensive at all, and if I can pay 5g to increase my spellpower by 42 for the whole night (and not have to reapply after wipes), then I definitely do not begrudge handing over 20g a week. But maybe that's just me - maybe this is seen as a substantial financial burden, even though most of us have gold coming out of our ears, and a quick whip-around of the Isle of Quel'Danas netts plenty of easy cash in a very short amount of time.
Is this really a massive drain on people's gold?
I guess I'm slightly disappointed because unlike most people, I actually get a huge kick out of farming consumables to give my character as much oomph as possible. On the other hand, I do understand that not everyone enjoys it, and not everyone has a lot of time to do so. Even so, I think oils are probably the least trouble to acquire and one of the least expensive of all raid consumables. Removing the only items (apart from flasks) that persist through death is a bit.. mean. Wiping hurts - being able to keep that weapon oil on regardless of how many times we wiped made me feel a little as though I wasn't pouring too much money down the drain.
I liked having that option to increase my spellpower or mana according to the situation, and have that last through countless wipes. I liked doing that little something more to boost my healing above and beyond the standard two elixirs and buff food.
On the other hand - it'll be one less consumable that I need to bark at people to use... so I suppose it's not all bad!