I felt like I had to say something due to the lack of responses. For me, Iron Kingdoms has become my second most favorite setting I've ever seen, and I've seen them all (or at least the D&D ones). I was extremely excited about the World Guide and Character Guide's releases, and I was not disappointed. You might be familiar with Monsternomicon, either from the rave reviews or from personal experience, and Privateer Press has easily lived up to that quality. I'm constantly day dreaming about new ideas for their setting, and I'm more jazzed about running games for Iron Kingdoms then any other game, besides my most favorite one. I highly, highly recommend it; the only complaint I have is that there isn't more material out for IK. Fortunately, if you check their website, Privateer Press just showed off the next sourcebook, and I'm all giddy.
Two thumbs up from me.