Allow me to be the first to congratulate you for purchasing this book. Sametime 8.5 is a very different product from previous versions of the product. What once was a simple offering that provided secure instant messaging with some web conferencing capabilities has now evolved into a robust, flexible, sophisticated communications platform. This book, written from the perspective of a Domino Administrator, will help you get the most out of this platform.
For reasons I can't fully explain, the major innovations in Sametime seem to come with the "dot five" releases and 8.5 was no exception. Consider, for a moment, this partial list of enhancements: