While Jans Wager's book reads a bit like it was written for a college course on Feminism and Film, it has some interesting points to make, especially about film noir criticism itself.
Her first valuable point is that the femme fatale in traditional film noir is not only fatal to the male protagaonist in the film, but she is invariably fatal to herself. This point, and its implications, is virtually always overlooked in film noir criticism. The "fatal fate" of the femme fatale is one of the major differences between film noir and neo noir. Wager goes on to explore this point through various movies, both of the film noir and neo noir style.
Wager explores how African Americans are either totally absent from film noir (even though virtually all film noir is based in American cities) or they are used, tangentially, to provide "hipness" to the male protagonist in the movie. For the most part, this observation is still holds true today with neo noir.
And finally Wager makes the point that recent movies, that are routinely labeled as neo noir, should rightfully be broken down into two categories, retro noir and neo noir--the difference being primarily how women are portrayed in the movies--both the femme fatales and the femme atrappes (trapped women, the good girls of film noir). If the women are portrayed as agents of their own destiny, (for good or bad consequence) and not simply as appendages of the male characters in the movie, then the style should rightfully be called neo noir.
If you find film noir interesting to watch and to read about, this book has some thoughtful points to make. But Wager's style of writing can be a little off-putting, both in its academic nature and its anti-capitalist, feminist slant.