Glyph of Dispel Magic is very good also considering its healing for as much as a renew tick does (and it helps alot against destro locks, frost mages, anything else that puts up magic's on you.)
Spec:
http://www.wowhead.com/talent#bMhZZGrMdrkrzzso
Twisted faith because currently our 4 set is nonexistent and pointless for shadow (I use 2 piece set bonus to sit at a comfy 1412 resil) so the spirit gives me 6% hit (plus you can reforge some spirit to haste if your over hit capped).
Imp Mind Blast isn't needed considering most other classes bring an MS into play (plus shadow orbs are gimmicky and unreliable at best).
I dropped Pain and Suffering because the SW
backlash above 25% is a joke (hits for like 800) and because i wanted to fit points elsewhere and i really dont mind refreshing pain on different targets.
Also, its well known now that Sin and Punishment can be removed via /cancelaura so i only took one point in it jic the healer doesn't know about it.
And mental Agility is fantastic i rarely have mana problems even through heavy casting and dispelling, Masochism and Sfiend with some spirit = GG right now.
Just my two cents