I've got this to the point where I think it's both accurate enough to be relied on, and functional enough to be actually useful, so I'm releasing it here.
Gear + Gem stats
All reachable Holy, Prot, Ret talents
Almost all raid buffs
All common glyphs (including 3.09's GoSoR)
96969 rotation comparing SoB, SoR and SoV
Stat weights including a graph (hardcoded for the moment)
Partial resists and glancing blows.
Naked stats for anything other than a level 80 human
A better Holy Shield model
Non-96969 rotations (i.e. Glyphed AS on cooldown, HoW at sub-20%)
Level < 80
Offspec threat talents like Holy Shock or Divine Storm.