a) A book covering broad aspects of dialog systems is definitely needed. This book does touch on many of important aspects/technologies and issues related to dialog systems.
b) The technical accuracy is correct and the manuscript contents will be easily understood by the research community. I think the community will find the book interesting and useful for improving state-of-the-art technology of spoken dialogue systems.
c) The manuscript addresses a highly relevant topic which is connecting the spoken dialog systems technology to real-life applications. The manuscript features contributions from recognized experts in the field. The editors have a long lasting experience in the area of spoken dialog systems research.
d) The material is factually accurate, very current, and very well presented. The breadth of topics makes for a comprehensive treatment of the subjects. The material reads very well and is adequately referenced.