I had pre-ordered these a little while ago and finally got my notice that they arrived from overseas (Netherlands I think?). Anyway I'm really looking forward to checking it out and I'll let you guys know more about it when they arrive. As of right now they're only available to those that pre-ordered, but I was told that they will be offered to the general public at some point. Cost for the three volume set was $199 for the pre-order. I don't know if they'll stay that price once they hit the streets.
UPDATE: The set arrived and I can easily say that they're more than worth the asking price. The books cover all known countries and variants of the AK as well as designs that have AK-like features like the Robinson Arms XCR, Sig 55X series, FN FNC, etc. The section on Russia takes up half of an entire book itself. Even more surprising was the section on the US, which takes up a little under half of an entire book. The US section covers all AK's/derivatives that have been available and are currently available here, to include Waffen Werks, IO, Century, and the earliest of imports and domestic productions. Every model shown has clear color pictures to go with them, along with a description along the lines of the Blue Book of Gun Values, but they don't mention prices (obviously). So essentially, if there were ever a specific model of AK you were interested in and wanted to see specs, history, and clear photos of then this will definitely fill that need. If you're just looking for a general history and catalogue of various country AK models, then I would still recommend "The Grim Reaper". This book is definitely for those that are REALLY into the AK, and would be great for people trying to build less than common variants or a certain experimental model of AK. Also, I'm not sure if it's regulated to the pre-order, but the set I received was signed by the author. A very nice touch that I didn't have to pay extra for unlike my copies of "The Grim Reaper".
Link to the pre-order.
ETA: Just saw this pic which shows some really good closeups of the AKMSU.