It is a worthwhile book for anyone new to SQLServer 2008 but the more experienced DBA might find it a little light on content. I say this having been a DBA since 1993 and I found this was very typical of almost every Microsoft technology how-to book where most of the pages seem to be from screen grabs the accompanying text to a large part walks you through what has to be done in each screen so the topics are a bit spoon fed and online SQL help has much of the same information already. I wrote IT books myself a decade ago so I have an idea how the wiring process evolves.
It does appear to be no frills and working through each section front to back if you have the opportunity and hardware available you can create the different HA options easily enough. At one client using SQL 2008 and there is a team of new DBA's and the book saved me writing a lot of the basic notes on the setup of the HA processes for those that had never done it before to follow in a test lab and for that it is good. However, wander off topic and you might get into trouble and it is a little weak in some areas and online SQL books did plug more than a few holes.
Question: Why jump in and write about clustering up front? That is the more complex of all the possible solutions and probably the least likely to be employed anywhere. I'd have changed the book order a little and put clustering after the sections on Mirroring but before the section on Virtualization as clustering requires more hardware elements to be configured and shared storage and configured from the start of SQL 2008 installation whereas mirroring can be added to almost any current setup, and suffices in most situations, with far less hardware configuration.
The book does not explain any migration paths from different legacy SQL Server environments (e.g. SQL Server 2005) and that will be needed in an enterprise, especially where transaction log shipping is probably already used. Many clients I yhave worked with use Transaction Log Shipping with a delay of 4 hours at least to cover hardware failure issues as well as typical user error of data deletion. Mirroring or clustering are often 'added' to an environment not put in day one.
I would suggest some more real scenarios are at least walked through to cover how the mirroring option at least could be used especially with applications using ODBC and Java and might have been worth including, there isn't anything on failure using these as connection methods only Native SQL Client are covered and the discussion of the monitoring is a hand ful of lines only.
I say this as a huge number of client applications still use ODBC or Java and HA is being added to databases to protect any enterprise from hardware failure. HA is all about protecting from failure and in depth notes on notifications, configurations of alerts and messages for database, processes or jobs is missing. To configure a real environment will require this extra information.
Some sections that explaining what the tools are, like the Hyper-V Manager Systems Centre Enterprise Suite feel like padding for 4 or 5 pages and do not provide any useful content at all. A visit Microsoft Technet will provide a lot more information.
A worthwhile book to get started on SQL2008 HA options but certainly not an indepth reference on the subject.