This is Doctorow's first novel, and it's getting lots of buzz from the way that he and Tor Books have chosen to market it. Rather than making an excerpt available for download, the entire novel has been released as a freely redistributable e-book. Cory has a whole page about it.
The book is set in a post-scarcity future. What that means is that technology has developed to the point where physical resources are easily available in sufficient quantity that it is no longer economically feasible for people to profit from their sale. This has made our current concept of money meaningless. In its place has come an economy of status. For reasons which never became clear to me, this status currency is called "Whuffie".
The mechanics of Whuffie are never really explained, but they seem to be tied in to the fact that people have basically all gone cyborg by having small computers implanted in their bodies. This computerization allows ubiquitous communication, extraction of the status information that makes Whuffie work, and, most importantly for Doctorow's plot, backup and restore of human minds. Near the beginning of the book, the main character is murdered. And restored from backup. The rest of the book is part murder mystery, and part engineering adventure.
The engineering adventure comes in because the main character is part of an adhoc which runs Disney World. In post-scarcity society (called bitchun society, again for reasons that elude me), large corporations don't run things, instead groups of people who care spend their time and energy supporting activities that are important to them. If the existing group starts slacking off, a new group with energy and bright ideas will come along and take over. The main character in the book finds himself in the midst of such a takeover.
Doctorow has imagined a fascinating future society and has woven an interesting story around it.