This fight is a extremely tough. Especially if it's a Mutilate Rogue/Dreamstate Druid. It's also really long and very difficult to win.

You'll want a Felhunter for this. The fight basically revolves around steady pressure on the Rogue and the Druid, preventing the Druid from drinking, and alternating CC on the Rogue to prevent him from being on your Warlock. This is achieved through rotations of Frost Shock and Fear, which is more or less determined by what the opposing team's Druid is doing. If the Druid is actually going to be able to land a root on your Warlock, a Fear on the Rogue prevents damage to your team for the duration of the root, at which point you can resume kiting. Your Warlock can also take this time to DPS or drain the Druid or Rogue and you can take this time to drink.

Most of this fight will be spent with you Frost Shocking the Rogue and your Warlock DoTing/running away/nuking/running away/renewing DoTs/ nuking the Rogue, which very slowly drains the Druid's mana.

The Druid will use lots of CC throughout the fight, mostly roots on the Warlock to let the Rogue catch up. Fear the Rogue (or use Grounding Totem) whenever this happens, as your Shaman's shocks will be on cooldown from Rank 1 FS. Take this opportunity to DPS the Druid heavily, if in range, or to DPS the Rogue heavily, making the Druid (hopefully!) fall behind a bit, and having to spend more mana to catch up. You also need to drink whilst your Warlock is fearing the Rogue. If you want, you can drink behind a pillar, or in LoS but out of range of the Druid - if the Druid taps you to stop the drinking your Warlock can wreak havoc on him then.

Just continue this until the Druid is OOM or a burst opportunity arises in which you can kill either the Druid or the Rogue fast, without them having time to react or prevent it.

Obvious tips:

• CoEx isn't absolutely useless. A human being cannot instantly remove it, no matter what. Often it takes 2-3 seconds for a Druid to remove it from someone if enough pressure is being applied. You can use this and twist it with shocks or drinks. It's up to your playstyle.
• If the Rogue is Mutilate, try and prevent any applications of poisons, as it's very difficult to remove them once he starts getting them stacked up, but once your Warlock is initially free, and if you prevent roots, or prevent the rogue from catching you if you do get rooted, it's not that bad.
• If the Rogue is Shadowstep, you basically just have to spam cure poison every 45 seconds.
• If the Druid is Dreamstate, be prepared for a LONG fight if neither of you make mistakes.
• Drink lots or you'll lose.
• You can also use Earthbind in place of FS. If the Rogue switches to you, you should be able to live longer than their team. Especially since you can just put Earth Shield on yourself and they can't remove it from you.
• Warlock Perspective: In my opinion, Dreamstate/Shadowstep is pretty much as irritating as this lineup comes as far as specs go. We had a 15+ minute match against this. I ran a Voidwalker to mitigate damage, but the Druid simply could regen more mana popping out and tossing out lifeblooms and hiding again than Komaya could healing me and having free reign to drink. If they do switch to kill your Voidwalker, run behind a pillar and resummon it while they're killing it. If the Rogue comes out to stop you, Frost Shock him and pull the pet back (the stun only lasts 4 seconds or so). Doubtful the Druid will be able to kill it by themselves in time. If the druid comes out to stop you, the pet will be coming anyway, and be in los for heals. Don't be hesitant about doing this at all. Basically you run this over and over until they make a mistake, and then you burn either of them. Save your Deathcoil for this point unless you're going to lose without it, then try again in 2 minutes.