I will stay Shadow until the new dual-spec interface arrives, then I will be Shadow in PVE and Disciplin in PVP.
The only thing I'm confused about is that they don't want to make Shadow Priests a DoT-class, but still we only have 2 decent nukes (Mind Blast and Mind Flay). And Dispersion is a "meh"-talent. It's not bad, it's actually awesome, but it feels like a "meh"-talent because it's a 51pts talent which does nothing more than regen mana and reduces damage by 90%.
I'd like to see another nuke spell there instead of a survival talent, since Shadow Priests are ment to be facemelters.