I recently got hold of a copy of this book, and I was suprised about its actuality. It came out 6 years ago, but the main lessons are as valid today as they were when the book came out.
Its content is quite original. For example, I have not seen the seven design concepts for navigation in cyberspace elsewhere:
linking, searching, sequentialization, hierarchy, similarity, mapping, agents. I found those useful as guiding principles for the design of my own Web sites.
I also liked the chapter about algorithm animation, which has been around as a concept for quite some time, but has never really picked up.
The writing is somewhat academic in style, but well worth digging in.