If you are looking for a book that gives you the ins and outs of Team System, this is not the book. If, on the other hand, you would like to know what Team System is, then this book is fine.
I did not get a chance to get a PDC version of the book, so I am not sure exactly what was in that "beta" edition. I will take the other reviewers word that this book is very much the same edition. It is quite common for authors to simply fix chapters from beta to final release, so this is both a common and accepted practice. Given the advice, however, I would probably not own both.
I have been using VSTS since the first beta that had its bits. I am, overall, impressed with the tool, as well as the MSDN online articles on the product. I was looking for a book with a bit more depth on the subject and there are some notable portions in this book, although most of the book is far too simple for my tastes.
What do you get?
The first three chapters are an extremely high level overview of Team System, including the Team Foundation Server. They are useful for a foundation on the product, but anyone with any type of exposure will likely skim through these chapters.
The next four chapters deal with the four roles (Project Manager, Architect, Developer and Tester) across the products (Team Foundation Server and its hooks, Team System Architect, Team System Developer and Team System Tester). These chapters have a bit more meat than the first three chapters, but are stil fairly high level.
The next two chapters are a bit deeper. Chapter 8 deals with MSF (Microsoft Solutions Framework) and is a decent overview of how MSF works, for those with little or no exposure; It is not, by any means, a full featured tome on the subject. Chapter 9 focuses on extending Team System and has a few nice code samples; most of the work is far too simple to make up for the shortcomings of Team System (for example, the build engine has to be customized for Continuous Integration (like using Cruise Control with nAnt for a truly automated build on check in)).
The final chapter of section 3 deals with deployment and closing out a build cycle. There is not a great deal of detail here and it primarily focuses on the reports available in TFS.
Of the two appendices, the first is probably the most useful as it provides context for how Team System is used from end to end. It is fairly basic information, but does deal with how to recognize Release Candidate time. The second is not much more than a text only listing of some of the visual elements you can use in the designer.
Don't get me wrong, I am glad I have this book, as I have learned a bit more Team System through the book. I wish it was a bit deeper, but there is certainly a market for intro level material in this product.
My recommendation: If you are a beginner with Team System and want an overview with a bit of meat, this book will fill the need. If you are already familiar with the product and looking for a full meal, it would be best to wait for other books on the product.