Jeffrey Zeldman says Intertwingled is about information architecture:
"In the information age, we are all information architects, says Morville in this fresh and fascinating take on the discipline he played a huge part in creating. Drawing on nature, culture, history, and science, plus decades of deep personal experience helping major clients, Morville finds new and profound meaning in the business of helping users to find their way."
Brenda Laurel says Intertwingled is about interaction design:
"Intermingles great thinking about interaction design with deep dives into spiritual, physical, and personal dimensions. Morville’s generosity with his own stories enriches a work of great insight on a topic that is ironically not seen as personal. From systems thinking to culture and politics, this work is deeply and diversely informed. Intertwingled is required reading for cultural interventionists."
I hope you'll give it a read, and tell me what you think it's about.