You've dealt with automata and the Wretched on the Isle of Quel'Danas. You've slain demons and blown up the transporter at the Throne of Kil'Jaeden. Are there more Shattered Sun-related dailies left to do? You bet! There are three quests that are assigned in Shattrath, and here's one of them: Gaining the Advantage. Posts on the other two are coming shortly.
Allegedly, some people in Stormwind can make oils that will help in the fight against the Legion, and they need Nether Residue to do it. This quest is assigned by Emisarry Mordin who paths near the flight master.
For this quest, all you need to do is be a skinner, herbalist and/or miner, and go out and do some gathering. Any Outlands herb (not Golden Sansam or Dreamfoil), ore node, or (I assume) skinnable mob has a chance to drop Nether Residue, of which you need eight for the quest. The drop rate on herbs felt like around 30%, possibly higher on higher-level herbs.
So it's a fairly easy quest to do, and as a bonus, you get some herbs/ore/leather. Go on back to Shattrath to turn it in, and be rewarded with 16g, 250 Shattered Sun rep, and
two one Major Rejuvenation Potion.