Overall, this is a light book -- a very quick read, and most of the stories don't really plumb great emotional depths (though I've read Dan Savage's story twice before, and it STILL made me tear up). A number of reviewers have pointed out that, although this book sets out to show the different faces of modern love, the selections here are overwhelmingly heteronormative. While I do think that the book could have been more diverse away from a heterosexual couple still being the central unit of the family, this selection does a great job of showing the diversity found within even that narrow world (and there are a number of non-heterosexual unions as well).
What I liked most was that most of the writers did a great job of remaining self-aware, searching, and non-sanctimonious. Most were merely living their lives, searching out an arrangement that worked for themselves and their loved ones; perhaps what would most shock a reader who firmly believes in the value of the "nuclear" family is how "normal" almost every household is, whether it is an polyamorous marriage, a mixed-race open adoption, or a forty-year old woman living with her female lover and two children. People are just people -- they lead their lives, do the best they can, and family is family. Only a few writers paint their own living arrangements as soft-focus, pentacles of domestic bliss that not only can but should be emulated by everyone else. Luckily, there are only two of those (if I remember correctly), and one of them ("Unassisted") is written in such horribly florid prose by a doe-eyed hippy that its laugh-out-loud humor value more than makes up for its inclusion.
This collection is not as radical or ground-breaking as the publisher seems to present it, but a good read.