This is the kind of book that I would expect to be published by Microsoft Press (which reminds me that it is a long time since I last had contact with that part of Microsoft) because it is written by two members of the team responsible for developing the product that it addresses. I think that provides an assurance that they know what they are writing about.
The second point I always consider when looking at a technical book is the quality of writing. This book meets my needs in this respect. I find the text easy to read so that my time can be spent understanding the technical content rather than wasted trying to cope with an author's poor communication skills.
Now what does this book contain and who is it for? This book documents the extensions that Microsoft has added to C++ to allow its use as a language in the .NET environment using CLR (Common Language Runtime). This is not the place to go into the merits of MC++, but I will mention that Stan Lippman went on record at the ACCU Spring Conference with an assurance that the many issues that C++ programmers have with the current release will be addressed. As far as he is concerned the VC++ team are determined to get much closer to support for a full standard conforming C++ + Managed Extensions. Currently MC++ not only adds many extensions to C++ but alsoseriously restricts your use of C++.
This book assumes that you have adequate alternative documentation of .NET and of CLR. It does not cover changes between VC++ 6 and the current release. It is not a book about Visual Studio or the about the base and framework class libraries (BCL& FCL). However that means that the authors have written a book that is very clearly focused on the needs of a C++ programmer faced with decisions about whether to use managed extensions or not. It gives good, clear advice supported with above average code examples.
While it is true that you can find almost all the information in this book in other Microsoft documentation, you would have to spend a lot of time searching for it. I have no doubt that if you need to consider using MC++ this book will help you. And once you have decided to take that development path, this book will assist you in doing so.
The only caveat I have is that readers of this review should note the year in which it is written. I doubt that the shelf life of this book will much exceed three years because by that time I fully expect Microsoft to have released a new version of MC++ which will be less restrictive and closer to a fully conforming, though extended, C++ implementation.