Resources:
  Health (also low health alert?)
  Mana?
  Alternate power
  Shadow Orbs (either this or a "Devouring Plague is castable" display; not sure which is better)
Timers:
  Rotational:
    SWP and VT (can probably be just a dot, hidden unless VT has less than a third left in which case one color or SWP does in which case another)
    Insanity buff |
    Mind Flay     |
    MB            |-- EventHorizon
    SWD           |
    Divine Burst  |
    Void Entropy?
  Other:
    Leap of Faith
    Will of the Forsaken?
    Desperate Prayer
    Dispersion
    Fade
    Mass Dispel
    Silence
    Vampiric Embrace
    Shadowy Grasp
    Combat consumables
Hostile nameplates (should have shortened names, health bars, cast stuff, and shortened absolute current health)
Something for multi-DoTs (probably nameplate debuffs - EventHorizon mouseover thing would be nice if that gets fixed)
Target name and raid icon
Target health (bar and shortened absolute current number)
Alert for target health being below 20%
Target power (but only when it's actually useful to know about - depending on how target power is used in WoD, maybe just let BigWigs handle it)
Target cast bar
Something for Leap of Faith (probably raid frames, since they can also be useful for selecting people for boss fight mechanics)
Range display for Divine Burst + other things (so probably just an approximate number on the target frame)
Boss timers
Special action button (or hidden and keybound, but it appearing also works as a visual alert)
Alert for target having a dispellable buff
Alert for friend having a dispellable debuff (make a GridStatusMassDispel?)
Important target buffs and debuffs (in the same frame?)
Important player buffs and debuffs (in the same frame?)
If using raid frames, friendly alternate power
Boss frames (with DoT timers, if that's still possible?)