Apparently Shadowpriests are completely fine in PVP.
We don't need a snare, because other classes have one. We don't need snare removal, because it would be unfair to players with snares. We don't need a way of getting out of melee range, because apparently we can tank, and have awesome healing with VE. Also, Holy has one with Body and Soul.
Oh, and the Developers didn't know that Mind Control doesn't give you the other players abilities in PVP.
So, there we have it. Shadowpriests are completely fine in PVP, and apparently the fact that there are only 9% of all Priests in the arena playing as Shadow over 2k rating (2v2s and 3v3s) is a coincidence.
We have decent escape abilities with Dispersion and Psychic Scream, too. Apparently.
At least he says there might be a chance that they could make the Dispel protection on Vampiric Touch actually do something next patch.
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.