I've been installing and supporting Windows Server 2003 machines for a couple of years and thought that I would get up to date with what Server 2008 has to offer by reading this book. However, it seems to concentrate much more heavily on explaining things that were already in Server 2003 than it does on explaining the new features in 2008. Barely anything on Hyper V, absolutely nothing on NAP (network access protection) and not a lot on several other new items. These are not just little updated things or things that are just slightly improved from server 2003 - NAP and Hyper V in particular are complicated new elements that anyone starting to use server 2008 would want to know about so I'm rather disappointed that they are not really covered in this book. Yet there are entire pages dedicated to telling you how a hard drive and the file system works, which to me seems quite out of place in a book like this.
Having said that, it did teach me a couple of things... but again these weren't really Server 2008 specific, which is what I bought the book for.
For anyone who is new to administering Windows servers and your first server is a 2008 machine, this book is ideal. For anyone who is very familiar with things in server 2003 though, I dont think it is worth getting in all honesty. You would be better off getting a few different books that cover specific things you are interested in, such as Hyper V or Group Policy etc (as group policy has been improved a lot in server 2008).