This book is a treasure-trove of ideas! It's set hundreds of years in the future, when humanity experiences "first contact." But of course it's not what anyone is expecting, and there are revelations and hoaxes and twists galore.
The scope of the book is so huge and complex it's hard to summarize it, but one of the major themes is trying to figure out and avoid the many possible fatal pitfalls of advanced civilization. One idea I found VERY interesting is that many people (politicians and extremists on both sides of the spectrum) become addicted to self-righteous indignation, which keeps them from rational discourse. And our society tends to just feed into that and make it worse, rather than realizing an addiction for what it is: the enemy of a mature and rational society.
This is the kind of book you sort of wish everyone HAD to read because there are a lot of clever and "important" concerns and ideas. I love the idea that diversity is vital to the survival of a species, that it brings "hybrid vigor."
I swear this book is very entertaining, too! Not just concepts and causes. There's a lot of great artificial intelligence stuff, genetically-engineered smart dolphins, extreme future sports, virtual reality Matrix-type mind trips, etc. Lots of adventure! Hopefully humankind won't self-destruct in any of the creative and plausible ways detailed in this book, but instead survive and thrive.
The ultimate message of the book is very hopeful and enlightening.
NOTE: Existence is slated for a June 19th, 2012 release. I was lucky to get an advance e-copy for review through NetGalley.