Looks like the ebook is available now, with the print book available very soon:
In this book, Ed Marzcak and I cover Apple’s Managed Preferences, or MCX from a practical standpoint. We discuss how Managed Preferences work, what they can manage, and some of the options you should consider. We cover several implementation scenarios, including Active Directory schema extension and even Local MCX. We also provide several step-by-step “recipes” for managing specific applications and features of Mac OS X. Written with Snow Leopard in mind, most of the examples and discussion is also applicable to Leopard, and in some cases, to Tiger as well.