I finally got a look at it in the book store yesterday. I thought some of the monsters were interesting, but there weren't enough to make this a must buy book.
Concordant Killer: Its' concordant sword acts as though it were holy, unholy, anarchic, and axiomatic all at once. Nice picture, kind of angelic but demonic at once. It may seem too much like the Rilmani though.
Demons:
Death Drinker: A demon that looks like a balor except it wears armor, and the facial features are much more skull-like. The picture has it reclining on its side. it's supposed to be very conceited, with a contingent of undead who bask in its glory and life-draining aura. It has an aura that drains life (1d8) from any creature next to it on its turn. Not really notable. It has the ability to gain hp from creatures it destroys, and usually cleaves into one of its followers if it needs an hp boost. This creature is a melee creature. It starts off at a +38 with its adamantine sword. Its most notable ability is its quickened greater teleport spell-like ability. As you can guess, its favored tactic is to teleport close to a spell-caster and full-attack him.
Kastighur: The only new tanarri. It looks like a bluish scaly minotaur, but its face has no bovine features save the horns. It has golden armor bolted to its body. I think we're getting too many demons with bull-like features (ghour, bulezau, and goristro). The kastighur are hunters and trackers of the abyss. This demon likes to charge, and its powerful charge forces the creature to save or be stunned for 1 round. It also has quickened teleport 3/day, and uses this to set up a charge and stun spell-casters. It normally charges so that it has 15 feet between it and the victim. If that creature is still there the next round it closes the 10ft gap with another charge.
Nasrhou: A weird looking demon that is more like a simple predator than anything else.
Whisper Demon: Should have been loumara.
Vitreous Drinker: An undead that drinks the eyesight of other creatures, these are the eye covered creatures in the Wizards ad with the ravens. I think they're the coolest creature in the book with their incorporeal ravens who hover about (very creepy).
Yugoloths: Corruptor of Fate: Assassins and trackers of the yugoloths. They are kinda puddgy with skull-like faces. They have an unluck special ability which forces opponents to reroll attacks against them.
Voor: Watchdogs of the yugoloths. They are similar to the canoloth except they have tentacles growing out of their backs. There is an interesting quote of a horned devil (cornugon) that mentions how the Voor were the perfect soldiers: strong, doesn't ask questions and perfectly expendable. I thought the yugoloths were manipulating the devils and demons, not the other way around.