As a technical writer I have been using the 2nd edition of this book for years as a primary resource. Obviously, its 1998 copy write date has made the 2nd edition more and more dated as time goes by.I'm not going to go to specify which entries Microsoft has updated for this edition...I'll simply say that I have yet to look for an entry that should be there that wasn't. It's exactly what you'd expect for a new edition...it seems to be thorough.
What I did like is the book's new organization. It's divided into two sections:
1. General Topics
2. Usage Dictionary
The Usage Dictionary is essentially just like the 2nd edition, with all the latest XP terms and stuff. It's what I expected to get when I purchased the book.
The General Topics section is this volume's great improvement. Whereas topics like procedure guidelines, screen terminology, and grammatical suggestions were scattered throughout the 2nd edition (i.e., listed alphabetically) the editors realized that the 3rd edition would serve readers well if these types of entries had their own section. Consequently, the first 182 pages of the book contain chapters titled
1. Documenting the User Interface (includes naming conventions for screen terminology, dialog boxes, menus, etc.)
2. Content Formatting and Layout
3. Global Content
4. Content for Software Developers
5. Web Content
6. Indexing and Attributing
7. Tone and Rhetoric
8. Accessible Content
9. Common Style Problems
10. Grammatical Elements
11. Punctuation
12. List of Acronyms and Abbreviations
This first section is so good, in fact, that it should be considered standard reading for anyone who's going to be writing technical documents. It's comprehensive yet easy-to-read.
The book also comes with a CD-ROM that contains electronic versions of the following:
1. Microsoft Manual of Style, 3rd Edition
2. Microsoft Computer Dictionary, 5th Edition
3. Microsoft Encyclopedia of Networking, 2nd Edition
These e-books are not as convenient to use as the e-books that came with the 2nd edition (the new Style Manual e-book is just a big PDF), but they are nice resources to have...and I'll take what I can get. Certainly not a bad deal for the price.