This is one of my favorite PVP Builds. Unfortunately, you will rarely see this spec in Arenas. This is pretty much designed only for battlegrounds.
If you still want to choose this spec then you are in for a lot of fun if you do battlegrounds. This spec is deadly and in large scale groups can wreak havoc on the enemy team. Shadowfury provides a nice stun and aoe damage, conflag is awesome for that extra burst damage when combined with shadowburn. You'll be immune to fire and shadow spells 30% of the time and you'll be able to pump out instant cast shadowbolts if someone is meleeing you.
