Two thirds of this book are roughly the same as the previous version, but if you want to find some new gems of information you should read it all. Reading it all was no exercise for me. It reminded me of some issues I had forgetten and am not using and I was pleased to be reminded.
The first part on the Cooper Process is excellent and gives lots of insights and new information. The new chapter on Visual Design is a bit simplistic in my view, but if you know the matter you shouldn't be bothered by that.
All examples are updated and fresh. Some new pictures of Cooper project help in making the case. I particularly liked the interactive pie charts for example.
As the Web is moving towards Rich Internet application and the desktop applicatios are moving towards Rich Internet information applications this is the best and most up to date resource for Interaction Design we have at this moment.
I read it in a weekend. I bet you will too...