http://www.wowhead.com/?talent=bxIMuhRtMcsifotfxzh
That's probably what I'd do. Don't pick Divine Aegis without Holy Specialization. And you don't need Grace in PvP, specially not 1 point. Also, you need Unbreakable will, for PvP it's better than Twin Disciplines. And Silent Resolve > Absolution, you cannot have your shield being dispelled.
@Sederix; Disc is another healing tree, yes. Still, not much has changed for it's first few talents though, they still work as well with Shadow as ever.