I'm reading this now and really enjoying it. Oryx and Crake is one of my favorite books- and if you like dystopian futures, and books about massive human die-offs, this one will appeal to you. It's not a sequel to Oryx and Crake but runs parellel to the timeline and many of the same events are covered.
She really does her homework on genetic engineering and imagines some amazing consequences. The Pigoons with human brain tissue, rakunks and other fauna and flora from the previous novel feature prominently.

Even though I'm only halfway through, I can already heartily recommend this book for people who like dark science fiction with some deep ideas. [hands in book report to Siftbot]