Semi-official Blizzard answers regarding Shadow Priests, as they seem to be really impatient:

Question 1: What does Blizzard see as shadow priest roll in pvp or pve situations?
PVE: I dont pve much but from my understanding there are aoe monsters is this the niche you intended them to fill in pve? I once saw a blue saying that they didn't want anyone filling that niche!
You're a dps class that focuses on dots and "stealing energy" from opponents. I'll write a prettier version for the official Q&A. Shadow priests can do single target damage and now in LK can do AE damage as well. 

PVP: As you all may know Priest are the only class with TWO healing trees. Did you want our dps tree to also have a strong healing component through Vampric Embrace? I often hear shadow priest refered to as the Pre-BC caster tank, are there any intentions of turning shadows priest back into this role anytime soon? 
Yes on the VE part. "Caster tank" as a role is a little risky. It basically means that melee have to close the gap to finally do damage to you, yet once they do... they still have trouble hurting you. I know that makes you want to say "But melee are crushing us right now!" That might be a problem, but doesn't mean the right answer is to have non-fragile casters. You are probably tougher than mages, and still have decent escape mechanisms with Dispersion and fears. 

Question 2: Was mind flay always intended to be our "filler," damage spell instead of a nuke or was it ment to be a mainly pvp spell? If it wasn't are you intending to give us a nuke? I ask because to my understanding shadow priest scale very poorly with haste which brings me to my next question. 
We don't really design every caster around nukes. That's kind of a mage deal where they emphasize one main spell. We want the other casters to feel differently, to have rotations. Mind Flay is part of that. 

Question 3: Does blizzard intend to make haste effect dots? As you all may know this would help with some scaling issues and I don't see why they couldn't do this, they already did it with crits! 
It's something we're talking about. Haste is a problematic stat for a number of reasons. It isn't always good for example if you don't have enough room in your rotation to fit another spell. It isn't good if you're GCD capped. Now, it's okay -- in fact preferable -- that stats aren't equal for everyone. We like that not all casters would look at say a ring with haste, crit and spirit the same way. 

Question 4: Does blizzard think that dispel protection is a problem for dot heavy casters? If you do what are you planning to do to fix this? If you don't why not? I understand that vampiric touch has a penalty for being removed but I just don't feel like it is strong enough or even compares to it's much stronger version unstable affliction. 
We think the whole dispel protection game needs to be overhauled. Buffs should be valued for their buffs, not for whether or not they can protect other buffs. We need to change this whole system to something more sane. Whether or not you have a dispel, and whether or not your target is vulnerable to it has just become way too important. You are right that the VT penalty is so low as to be silly, and that's something we would like to boost for 3.2. 

Question 5: Alot of players feel as though replenishment should belong solely to shadow priest, we understand that you would like to "bring the player not the class," but honestly could you say that having a unique class/spec ability is such a bad thing? 
Yes, it's a bad thing. It's good if you're a shadow priest wanting a raid slot. It's bad if you're the druid or warrior who can't come because the raid leader feels like they must bring the shadow priest in order to raid. We want the challenge to be the encounters, not the logistics of building the group. 

Question 6: It takes shadow priest significantly longer to set up our damage than other classes. Would it be in your intentions to add an initial damage component to vampiric touch and make it instant cast to help alleviate some of the wait-time for damage? 
I think there is something to the set-up-your-damage issue, but at the same time, dots also have a lot of benefits over direct damage spells. We would not want any spell that Shadow priests felt like they could just cast instead of doing their rotation, and if the instant-damage spell was weaker than the rotation, it would likely see only situational use (though maybe that's a fine niche). 

Questions 7:Are you planning on implementing a snare/root for shadow priest? Shadow Priest is currently the only caster that has no snare/root abilities. These types of abilities are essential when we are not able to tank damage and wear cloth. 
We don't want to give every mechanic to every class if we can help it. Just above you asked if it was a bad thing to have some unique mechanics. Saying no isn't the same as saying everyone can have some mechanics. We intend for the Shadow CC to be things like Psychic Horror and Silence, and to a much lesser extent, Mind Control. 

Question 8: Shadow priest are always triggering our global cooldown but have no way to make it shorter. Are you planning to implement maybe a talent to reduce our global cooldown? 
We wouldn't do it through a talent, but we might let haste do it. Remember, the global is there for a reason. Having too many abilities short-circuit it will ultimately have consequences. 

Question 9: : As you may know shadow priest have a fair amount of mobility issues, are you planning on adding a short immunity to snares after fade is used? ( Improved Fade ofcourse.) 
No. We would be more likely to nerf snares. We don't want to have an arms race of snares, then snare immunity, then the snare that can't be made immune, and so on. 

Question 10: Are you planning to add Body and Soul to the shadow tree? 
No.