I might.
I agree above, on Interventions, Celestial Choirs, Paladin stuff, Miracles, Quests, pre-destined fate, Divine Feats, and such. However, I would like a few Different things, aswell:
Speciality priests. Not Prestige classes, because it takes forever to get into them, as well as a spesific kind of tooling Just to get into them, but ways to tailor your cleric FURTHER to represent more about their god. Domains, yes, good start. But, they should get More variety, then just the armor-wearing spell casting clergydude. Note, that this could be a way to more balance the cleric: Sacrificing good things (Like the inabilty to cast battle spells for this, or sacrificing armor proficency for this, etc) so they Are more like their deity.
Other then Divine good. We get the point: Cleric and Paladins are good and holy and bla bla bla. But there also needs to be info on how to work Good with other classes, and NOT just focus on the Divine portion. C'mon, let's see some stuff for Good Rogues, Spellcasters, and Fighters. Even good Barbarians (WAAAY too many CN barbarians).
Organizations that are well detailed, and not just bland ol' undead slaying guilds, or paladin orders. I want to see something like the Harpers. Something where good people work descreetly, and stuff, to work good. Not just 'There's evil! Let's smite it!'. Some Chaotic Good, and Neutral good representations, and organizations. Not just Awful good.
A good, well working example of ALL the aligments, showing outlooks, character actions, and thus thus, Indeptly.
Ways to do Good monsters of often Evil races, and how to incorperate them effectively.
And, I don't think it should be a double-book. That means both sides would either have less material then a product by itself, and even so, it'd be THICK! No thank you.