Mastering Exchange Server 2010 book

The Exchange Server 2010 book is now "on the streets" and I have gotten a lot of good feedback from people. However, one thing I want to make sure that potential purchasers know. The book currently has no Database Availability Group (DAG) content. The book is intended for new administrators (new-to-product and new-to-version) rather than a technical "deep dive." Our original intent was to follow-up with an "Advanced" book. Not sure where that is, but we are looking at options for people that want DAG content.