Having read much of the detailed work on the capability approach, I was afraid Nussbaum's book would simply rehash ideas from previous works. Happily, I was quite wrong. The book lays out the capability approach in a very clear and concise way. It also provides a good discussion of the growing diversity within the capability approach itself as more people, particularly those with different backgrounds, engage with it and take the capability approach in different theoretical and empirical directions.
Despite it being early in the year, I can certainly say that Creating Capabilities will have a spot on my top ten books of 2011.