From the publisher's website:
New feats for characters focused on divine powers and spells should mean more than new metamagic feats, extra uses of abilities each day, and taking Weapon Focus with a deity’s favored weapon. Just as monks, fighters and rogues can use feats to adjust and modify their fighting styles, clerics, druids, rangers and paladins should have a range of options that let them adapt their divinely-granted abilities.
Spellcasters may wish to focus on learning new ways to use their divine spells (such as with Healing Benevolence), increase just one aspect of their spellcasting power (perhaps with Domain Focus), or master a priesthood that grants spells only after the caster’s blood has been spilled (with Blood Priest). There are also numerous feats nonspellcaster characters that are devout followers of a god can qualify for and find useful (such as Domain Acolyte and Miracle Worker).
With these feats a campaign can include priests who are not clerics, allowing gods of battle to be served by fighters with some access to the War domain and gods of magic and healing to have temples filled with celestial sorcerers able to cast cure light wounds.