The second edition of this book was issued in May of 2001. (ISBN 0961392142)
The changes and additions include "color reproductions of the many graphics of William Playfair, adds color to other images, and includes all the changes and corrections accumulated during 17 printings of the first edition."1
Personally, I can't wait to see it.
1. http://www.edwardtufte.com/793325881/tufte/books_vdqi