The first half of this book is basically just an analysis of The Lion, The Witch, & The Wardrobe, explaining how it mirrors the gospel message. Though not poorly done, it isn't exactly groundbreaking, either. Veith's tone is somewhat exclusive, leading me to believe this was not written for the benefit of those outside the Christian faith. And yet most Christians are already familiar with the allegorical themes in the Chronicles of Narnia, so I'm not entirely sure what the point was.
The second half of the book draws comparisons between Narnia and the more modern fantasy worlds created by JK Rowling and Phillip Pullman. The former struck me as equal parts ridiculous and unnecessary. Veith's summary of the Harry Potter books was so off base, I question whether he has even read them. In his own words, HP is ultimately about "the struggle for popularity", and readers have fallen in love with Rowling's wizarding world because it enables their "fantasizing about being popular and successful". Those are exact quotes. Whether you like HP or not, it is beyond me that ANYONE could actually read the books and come away with that conclusion.
Having never cared to visit the His Dark Materials series, I can't really comment on that bit. It did at least contain actual quotes from Pullman and passages from the books (more than can be said of the HP section).
Bottom line: This one's skippable, folks. There are better books on similar subjects out there. Read one of those instead.