The domains are useful for evil deities--don't have to give them all the Destruciton domain or Death domain for negative aspects anymore. However, it's a great book for spawning ideas, esp. if you want to add a touch of horror to the games.
For example, I'm working on an adventure where the PCs begin investigating a missing persons case, but discover something much more horrid. Something roughly along the lines of The Texas Chainsaw Massacre (minus the chainsaw). The Sawyer clan (or the Hewitt clan, apparently according to the remake), will be a bunch of mongrelfolk. As for Leatherface, I was thinking of making him a rogue/barbarian (for the sneak attacks & raging; may through in some fighter levels for feats & weapon specialization), with an enchanted mask (fear effects or along those lines), feats that boost up critical ranges & damage for his favored weapons (warhammer for sneak attacks & greatsword for slaughter), and at least the vile & impact/keen enchantments on said weapons (respectively) to boost up the damage potential (may throw in the evil enchantment, as well). He's supposed to be the toughest & most horrifying member of the bunch, though the other clan members will have their own twist, as well.
I hope it works at spooking the players (intended as a Halloween-time module/adventure), but also at showing them just how bad evil characters can be.