Changes are not expected in the stable release (page 24)
More...Reported on: 2005-07-21
In chapter 1. Introduction on page 24:
Section 1.4.2 talks about anticipated changes to the Debian project and system. As should become apparent when reading section 4.3.3, such changes are not to be expected in the stable release of the operating system, which is one of its main selling points. Thus, if you only track stable and have no interest in the surrounding project or new developments, you need not be concerned with these changes.
I keep a list of changes online to make it easier for you to track developments since the book's release.