The book covers COM+ component service support on Windows platforms. COM+ allows you to configure classic COM components including those (re-)written to explicitly use COM+ services as well as the new .NET components. The title of the book therefore is something of a misnomer - COM+ Component Services would have been nearer the mark. If you're looking for a lot of .NET information you may be disappointed; the .NET specific section doesn't occur until Chapter 10 - in a ten-chapter book!
That said, the book does give good insight into how to work with COM+ and how to write your applications to co-operate well with COM+ component manager. In particular, there are good sections on common pitfalls and odd inconsistencies with the way COM+ works - such things usually take a lot of effort and time to learn the hard way. This book will save you the hassle. The code samples are almost all in C++, although they are definitely more for information rather than production code as the author omits checking return codes for errors all too frequently.
One chapter of the book (Chapter 6: The COM+ Catalogue) I felt was more of a re-hash of reference information rather than adding anything significant to your 'how-to' knowledge. The chapter on security (Chapter 7), on the other hand, did a good job of explaining how to configure role-based security under COM+ and gave plenty of tips and caveats for security in a distributed environment. The text is, by and large, quite readable although in a couple of places it does get heavy going even though the subject matter isn't particularly difficult.
If you know next to nothing about COM+ services this book will bring you up to speed in a short space of time. If you are already highly conversant with COM+ then you probably do not need this book as it starts from assuming relatively little - if any - COM+ knowledge. You will, however, have to be familiar with COM and C++ examples. None of the examples use any framework libraries but stick to core COM calls so they should be understandable to all COM developers. This is a book I can see myself referring to during active development so I'd recommend it to programmers. If you were after a high level overview you'd be better off with a more lightweight book.