Stephenson is one of those authors whose books I get sight unseen. He has the irritating gift of writing so well that any writers reading his books wonder why they bother writing themselves.
FODIH (and the comma, incidentally, is correctly placed) is no exception. It charts the course of humans finally discovering how to upload their consciousnesses into digital media, and the gradual consequences of that. A large number of powerful presences fill the pages, and an equally large number of far-out but believable notions of what the future brings.
It's not for the faint-hearted at nearly 900 pages, but I enjoyed it. I always enjoy Stephon's books, curse him.