Yes, there's a gathering quest coming in the 2.4 patch. I actually didn't realize this until I got in there and started picking up quests. This one starts in Shattrath City, near the flight master. You are asked to collect 8 nether residue, which supposedly drops anywhere in Outland. I've done this quest 2-3 times on each of my gatherers to try and figure out the best way to complete it. Unfortunately all of my research is subject to change between now and release. It's pretty obvious to me that they are still tweaking drop rates. On the first day of mining I collected all 8 quest drops after about a dozen nodes. Two days later it took over 30 nodes to get the same 8 drops, so clearly the drop rate is in flux. Either that or I just had horrible luck on the second pass.
I started with Mining initially, I had another new daily in Netherstorm so I decided to try my mining there too. I didn't actually count the nodes I mined, but I know I didn't try to hard and I was getting over 50% drop rate so I'm estimating that I hit about a dozen nodes to get the 8 quest drops. I went to Nagrand the following day and visited 14 nodes, but only collected 5 quest drops. So I thought I'd head back for Netherstorm on the next round to see if the drop rate was still better there. Unfortunately this was when the nerf on drop rates seemed to kick in. On my second visit to Netherstorm I had to gather over 30 ore nodes, which took over an hour, before I finally got my 8 quest items. I was very annoyed and submitted a grouchy survey on the quest that day :(
For Herbalism, I started in Zangarmarsh on my first outing and after nine herb nodes I had zero quest drops. From there I flew to Terokkar and hit 5 herb nodes, scoring 1 quest drop. Herbs were a tad scarce in Terokkar and I wasn't excited by the drop rate so I kept going to Shadowmoon. I collected 6 herb nodes there and got 2 quest items, a decent improvement over Terrokar. Finally, I decided to try Netherstorm and got 5 quest drops from 7 nodes. This was prior to the nerfing that happened with mining, or at least that I suspect happened. Today I went back to Netherstorm to see if the drop rate was lowered for herbs as well and it took 24 herb spawns to collect my 8 quest items, which seems to confirm that the drop rate was lowered for all gathering professions. In general I think the drop rate is better in higher level zones, I realize my sampling was small but zero drops in Zang looks pretty damning.
With skinning, I started in Nagrand because it was close to Shattrath and has lots of beasties that I'm used to farming anyway. There's also another Sunwell quest in Nagrand, so it's kind of a nice way to combine your efforts. On my first attempt, I had to skin more than 30 beasties to get my 8 quest drops. I wasn't a terribly happy camper that day. The next day I went to Netherstorm to see if I could achieve the same increased drop rate that I'd noticed with herbs and ore, but I think this was after the supposed nerfing. I staked out a spot near Cosmowrench where the warp stalkers and such hang out and I skinned just over 30 critters to get my 8 quest items.
In general, I like the idea of this quest. It's pretty neat to be able to combine farming that you do anyway with a daily quest that gives you faction and a little coin. Unfortunately, as a daily quest it's looking pretty cumbersome right now. No one wants to spend 30-60 minutes on one daily quest. That's a waste of time for folks who are farming cash and/or rep when there are plenty of other quests that can be completed more quickly. However, if you view it as a way to further capitalize on farming you're already doing I can see how this would be a nice perk. I guess what I'm saying is, with the current drop rate I don't believe anyone will do this quest for the rep or gold. If Blizzard wants to make this quest comparable to other dailies, they need to beef up the drop rate so it can be done in about 15 minutes.
On a slightly different note, I also think that the skinning drop rate should be higher than that for herbs and ore. Since skinners have to kill every mob they collect from, I don't think it's reasonable to make the drop rate equal to other players who simply flit from node to node and only have to kill a handful of mobs doing it. Even though I have toons that cover all three gathering skills, I felt frustrated that my druid had to expend much more time and energy to gather her quest drops than the other toons did.