Best PvE spec for a level 85 Shadow Priest doing Heroics

I have been planning on respecing for heroics too. I took your tree and made a few adjustments.

http://www.wowhead.com/talent#bcrRZZGbGdMzrd0fo:MRkMRVV0z

The point in Phantasm got the boot because I have noticed very few times it would be useful in Heroics, and if you take it you are best taking both points because when you need it is not the time to hope it works this time. That point and one of the points from Mental Agility got put into Inner Sanctum to help lower the damage I am taking and make things easier on possibly undergeared healers.

I took a look at the specs that Jesta and FertZane posted, and I feel like both specs are missing out on something that, in the past, was largely considered to be a PvP talent. However, with the increased requirements for crowd control and interrupts in heroic instances, I really think you might want to consider picking up Psychic Horror, as well as picking up the Glyph of Psychic Horror. Reducing the cooldown on Psychic Horror to 1 minute puts it on par with the timer of a lot of boss abilities that can be interrupted.

I did notice too that FertZane's spec opted for 2/3 in Mental Agility and put the rest in Inner Sanctum. If you place the one point in Psychic Horror, you will have one additional point to put into Discipline, and depending on what kind of mana issues you are having, you may want to go 3/3 in Mental Agility with 0/3 in Inner Sanctum or go with 2/3 in Mental Agility with 1/3 in Inner Sanctum.

Personally, I went the route of picking up Psychic Horror, and 3/3 in Mental Agility because I was having mana issues initially, but I have been contemplating dropping it to 2/3, and picking up the one point in Inner Sanctum because I have stepped into raiding now, and it should help out the healers a little bit.

• Spec 1 (Psychic Horror & 3/3 Mental Agility)
• Spec 2 (Psychic Horror, 2/3 Mental Agility, 1/3 Inner Sanctum)