Dodelson is among the most active and knowledgeable specialists in the area of CMB (=cosmic microwave) anisotropies, both in theories of their origin and analysis of the observational data. With the launch of the new satellite-borne microwave detectors MAP (NASA) and Planck (ESA) in the next few years, a flood of data will pour in, whose detailed analysis will enable us to pinpoint all the basic parameters of the universe (expansion rate, age, ultimate fate, invisible-mass content, etc) to within a few percent. The subject is thus of central and growing importance, and there is currently no text that covers it more than peripherally. Judging by the draft of Chap. 1, Dodelson's style is clear, breezy and companionable. It should make the book suitable for self-study as well as a course text. I have no hesitation in warmly recommending this proposal.
I would see this book ideal for first year graduates (pre-doctoral) students. It promises to provide a solid introduction into one of the key areas of modern cosmology. I don't think there is serious competition. The Peebles and Peacock texts focus on cosmological models and on CMB in large-scale structure. One can ask whether the topic is too narrow for a text. I think not: cosmologists view the CMB as holding the key to the future of their field. It is the focus of much activity planned for the next decade, and attracts both astronomy and particle physics students.
After several decades of null results, CMB anisotropies are now becoming absolutely central to all of cosmology. Surprisingly enough, however, there is still no good up-to-date book (nor technical review article, for that matter) that explains the theory that underlies many of the experimental results that are being obtained and/or pursued. There is thus a desperate need for such a book. The book that Dodelson proposes will fill this void. I am confident it will be an outstanding book. Dodelson has been at the center of CMB research and has been near the major developments during the entire decade. His book is based on his vast and outstanding research experience, and on special-topics classes he taught at the University of Chicago on this subject. In fact, I can think of no better person to write the book.
In conclusion, I am very positive about the usefulness of such a book. The subject is timely and there is a real need for such a book. The outline is original and interesting. The author should be encouraged to keep it at the right pedagogical level which is well matched by the first chapter.