Strengths:

• Wound Poison Healing Debuff
• Depending on Spec - Shadow Step (Staying on target) / Mutilate (Amazing Damage)
• Mana Burn
• Dispels
AoE Fear
• Rogue's Cloak of Shadows can make it really hard for your Druid to CC.
• Removes Entangling Roots with ease.

Weaknesses:

• Abolish Poison removing Wound Poison and Crippling Poison
• Easy to kite the Rogue around Frost Traps
• Priest is easily susceptible to Viper Sting
• Heals are weak, need's to be in LOS of his Rogue more often when he takes damage.

Who to keep Pet on:
Priest

Possible Rogue Talent Spec's (Standard Spec's):
Rogues have Several Viable Builds

Possible Priest Talent Spec's (Standard Spec's):
Discipline
Holy

For a while, I used to tunnel vision on the Priest, I thought "I need to kill the person I'm draining.", but it takes forever when you have a Rogue beating on you and the Priest is LOSing you like a champ, only popping out to Mana Burn.

The way I play this setup after evolving my playstyle is setting the Priest as my Viper Sting focus, and I DPS the Rogue. My Druid Cyclones the Rogue when I have trouble getting range or when I get low on hit points. It forces the Priest to be in LOS of you so he can heal the Rogue so you can keep Viper Stings up every 15 seconds. When the Rogue gets Pain Suppression try chain Cycloning him so he can avoid getting healed as much as possible at this stage.

It's pretty basic, use Frost Traps, drain the Priest and DPS/Kite the Rogue. Between Abolish Poison, Wing Clip, Concussive Shot, Roots, Cyclone you shouldn't have trouble maintaining range on the Rogue after his initial cooldown burst.

The hardest part about this combo for a Hunter's is Mana Burn, a very aggressive Rogue/Priest team will attempt to Mana Burn you to 0, and will attempt a few sneaky Mana Burns on your Druid, you need to be on point with Silencing Shot. I only recommend using it to stop Mana Burns and a heal when the Rogue or Priest is below 20%. With coordinated CC's shouldn't stop you from drinking enough mana to easily stomp this combo.

Mutilate Rogue's are harder than Shadowstep because when they do get in range of you that Abolish Poison resist paired with how much damage they do can be nasty if your Druid gets Mana Burned. You have to be mindful of who that Priest is targeting and what he's casting, both you and your partner.

One of the main reasons why I suggest DPSing the Rogue over the Priest is because often times when you're chasing a Priest around a corner when you do finally catch up you eat a Psychic Scream and a nasty Mana Burn. When you are DPSing the Rogue, the Priest is forced to come into LOS for that split second to get a focus Viper casted on him.