This book introduces a new technology that promises a considerable improvement on the ASP.NET membership system. If you ever had to write an extranet, system you should be aware of the problems in setting up membership for your site. The Windows Identity Foundation promises to be an excellent replacement.
Therefore the book Programming Windows Identity Foundation - ISBN 978-0-7356-2718-5 at http://oreilly.com/catalog/9780735627185, is breaking new ground.
I recommend this book to all ASP.NET development teams. You should reckon on 3 to 5 man-days to study it and try out the sample programs and see if it can replace your bespoke solution. Rember this is version 1 of WIF and give yourself adequete time to read this book and familiarise yourself with the new software.
Some URLs for more information: