At the October meeting of the Boston DITA Users Group (held last Thursday evening at the DocTrain East 2007 Conference), Amber Swope of JustSystems reported on the Bookmap specialization in DITA 1.1.

You can find a one-hour Flash movie of Amber's presentation at

http://www.ditausers.org/tutorials/ditamaps/bookmaps_swope

We had some technical difficulty and Amber had to speak for the first several minutes without her slides.