I remember seeing a few reviews of this back around the time of CBR3, maybe? It sounded like an interesting idea, though some of the reviewers did warn that the premise wore a bit thin by the end. Personally, I thought it was a pleasant and thoughtful little novel - it is less than 300 pages, and feels like a short, yet developed story.
According to Brockmeier, the dead remain in the afterlife as long as they are remembered by the living. They have a whole large world, full of cities and streets, and life basically goes on as before. Some people live out their deaths longer than others, but in general everyone has a routine. However, suddenly there is a huge influx of people into the afterworld, followed by the city slowly but surely emptying out. A virus or plague has affected the population of the world, and as the time goes, all the people can basically narrow down their common acquaintance to one specific woman (some of the people don't even know how they know her, but she remembers them, however fleetingly, and thus they remain).
The novel also tells Laura's story, the lone survivor of the plague, who is cut off from civilization in Antarctica - her team has gone for help, but as the days pass, she realizes that she is going to have to follow them as her systems fails and she runs out of supplies. The novel at this point basically becomes a countdown to her death, and the tale of how she may survive alone in the cold wild.
The novel continues to return to the afterlife, and it is through the afterlife, that the reader gains an understanding of what happened and how the plague was able to wipe out the entire population. I liked that the reader got answers, even if the majority of the characters didn't. Overall, I thought it was an interesting take on the concept of death and what comes after, and the idea of life through memory reminds me a bit of themes explored elsewhere in a slighlty different context, such as American Gods. The gods gain their power through human worship and memory, and similarly the dead remain as a result of the memory of the living. Brockmeier doesn't try to answer what happens after the dead pass on from this level of the afterlife or if this is it, and it is irrelevant to the novel. Overall, I would consider this a successful story, though I hope that we are not doomed to this future - being set slightly in the future, many animal breeds that are endangered or threatened today are mentioned as extinct in the future before we finally destroy ourselves - I think the idea of humanity destroying ourselves bugs me less than the idea of us taking everything in nature with us.