Here's some things for the rest of you warlocks, and other classes who are playing with those warlocks to think over. First of all, in boss fights, I always try to have a food buff, a battle elixir, guardian elixir, and weapon buff. The food I usually use is Blackened Basilisk or Poached Bluefish to give the +23 spell damage (can usually find it in the ah, or get your cooking to 315 and make the basilisk). The batle elixir I usually use is Adept's Elixir, which gives +24 spell damage and crit. The Guardian Elixir I use is Elixir of Major Mageblood for extra mana regen. And I use Superior Wizard Oil for more +damage. You need these buffs! Think about it this way: you have to earn the right to wear your tier 4! Cherieo can make the pots, I can make the superior wizard oil and Maeda and I can both make the foods. Don't be afraid to ask for it, we'll be glad to help out if it means winning.
Next comes the bosses where we as warlocks are very important--
Curator: What happens with the curator is that he will send out "hateful bolts" to the person who is #2 on the threat list. So we found that a warlock with arcane resist gear who is constantly draining life on the curator works really well because if you have enough arcane resist he doesn't hit all that hard, and you can easily heal yourself AND life tap to keep going without the healers taking those hateful bolts for 6k damage. It's also important to have deadly boss mods because at 1 minute before he innervates you can throw on a curse of doom (and amplify it, too, if you have the amplify curse talent), because when he innervates he takes 200% damage, so that's a big chunk from that curse of doom, especially if it's amplified. So, basically, I usually stand near the tank to the left, but not close enough for the chain lightning to hit us, and put up my dots, and drain life/lifetap/dark pact until 1 minute until he innervates where I put an amplified curse of doom on him. Then it's back to drain tanking, keeping dots up, taking the hateful bolts until he does innervate, then blast him with shadow bolts (had a 11k shadow bolt crit against him when he was innervating once, it rocked). It's just rinse and repeat from there, and it lets the group worry about the annoying balls without getting blasted with the hateful bolts. I have about 298 arcane resist with mark of the wild buff, but I think 250 or so is a good target to get.
Shade of Aran:
Everyone is important in shade, especially the interrupters, but controlling the elemental adds that he spawns is where a warlock is handy in this fight. Once he summons the elementals, you need to banish one, chain fear another, and howl of terror the other two, even though it only lasts 8 seconds, it's 8 seconds where your raid isn't being attacked by two elementals. Also, a priest can help by fearing these two adds as well. It's a lot of hectic madness in this part of the fight, so try to keep your dots on shade, maybe throw a shadowbolt if you can, keep an eye on your mana to be able to re-banish and re-fear. CT raid assist is awesome here, the leader should give you an assist so you can mark the adds you've banished and single chain feared to make it easier to pick them up to re-apply the cc. The elementals last for 90 secs, so that's 3 banishes and 5 fears. Just don't forget about flame wreath and blizzard while running about with CC, because if the warlock dies, then that means NO cc, and if you break the flame wreath that's really bad for the rest of your party. It's a lot to juggle, but after a couple of fights you'll get the hang of it. Also, it's a good idea to soulstone the priest instead of the paladin here, because if the priest dies you lose another fear on the adds. Under normal circumstances I would usually soulstone the paladin because being a plate wearer he will tend to live longer and not waste the ss. But here for Shade, soulstone the priest because chances are you're not going to be able to recover from a wipe since everyone will be spread across the room anyway, and you'll want that priest's fear to help with the other two adds you're not banishing and chain fearing.
Illhoof:
Here is where it's so much fun to be a warlock. It also requires you to carry the maxed nether protection talent. In this fight, the tank will tank Illhoof, an offtank will tank kill'rek, and you will tank about 30 little imps. Illhoof will summon imp after imp in this fight, so basically you're going to be spamming seed of corruption. The way it works is that maxed nether protection makes it so that you have a 30% chance to be immune to fire/shadow spells when you've been hit by one of those schools. These imps continuously throw out fireballs, so you get them attacking you by throwing out seed after seed, and nether protection will proc so often that you will barely be taking any damage, and your cast time won't be pushed back. I found that putting seed of corruption on my action bar, and manually targetting the imps with the mouse works best instead of using tab, because sometimes they get spread out into two groups, and that's not good because if you're not taking care of the imps then they'll all target the healers. It's also important to have a paladin in your group with their aura that decreases spell interruption so that when you're not being protected by nether protection your cast time still isn't being pushed back as much, because you will be hammered by a TON of fireballs at some points, especially if the adds get out of hand when you have to life tap, pot, or dark pact. Sometimes you'll take a second to do one of those things and all of a sudden you see the screen fill up with imps, and it's a little panicking, but just be smart about who you seed, pick the ones clustered together, and then slowly make your way to the ones on the outskirt of the group. They'll go down, and then you can life tap and dark pact. You'll also want a blessing of kings or the mana regen one here instead of salvation, because you WANT threat from all the little guys, because it's your job to be taking their fire bolts. Now I opened this by saying that this is where it's fun to be a warlock, because if you check the DPS meter, you'll find that you're doing 1600-1900 dps the whole fight, and your spot on the threat meter is through the roof. You don't have to worry about pulling aggro from the tank on Illhoof, because he's not affected by the aoe from seed of corruption. And you also aren't concerned with the person being sacrificed, you just have to keep your mana and health up, and the imps down, and the fire bolts on you. You also may want to consider mana regen food instead of +dmg food here, as seed of corruption is a very mana intensive spell.