Jurgen has written the book that should've been written long ago. He has nicely outlined what an Agile manager should be doing, which is something that has been painfully absent from Agile movement for too long. We need manager, but there hasn't been any thorough and well thought-out guides for their work.
Each of the six dimensions of Agile team management is approached first in theory, then by providing concrete advice. I liked this approach as it provided good explanations why something was recommended, and much of the success in Agility is founded on understanding what Agile is and why it works. Armed with that information, an Agile manager is much better equipped to handle situations for which there are no pre-existing guidelines (and there will be many such situations).
I wish every manager in a position to lead/manage Agile teams would read this.
To quote a friend, "the only bad thing about the book is that I didn't write it."