I'm still up in the air on this book. Eberron didn't really interest me (except in the fact that it's obvious where WotC was sending their talent for the past six months), but I could probably pick this up and have a majority of the Eberron monsters without needing to buy the campaign setting. The problem I have with this is that I don't really want warforged tramping around Greyhawk. Many of the Eberron creatures seem to serve a function in Eberron itself, but would just be conspicuous add-ons in other campaigns.
Sadly, it would boil down to me buying this book for maybe a dozen creatures. As much as I would like to have the Kenku, Flind, and Redcap as well as some of the interesting plantlife (Thorns, Wood Woads, Topiary Gardens, etc.)...I'm just not sure there's enough here to warrant the purchase. I still only use about 20% of what's in the Monster Manual II. Maybe something will change my mind, but...as more an more of the mainstream D&D books fill up with Eberron material (a trend I see continuing in the future) it gives me a feeling of exclusion for those of us who aren't interested in another campaign setting.