This is a wonderful text - much more accessible than Anti-Oedipus; however, it is not a faithful representation of Nietzsche's philosophy. Deleuze is a psychoanalyst, and he has a (bad?) habit of turning Nietzsche into an analyst, as well. If, however, one is willing to accept that we all tend to interpret our favorite philosophers as representatives of our own convictions, and that we should consequently read this text not as being about Nietzsche so much as the way in which Nietzsche can be used to understand a particular Deleuzian psychoanalysis of power, then all is dandy. . .
Deleuze develops the notions of active and reactive forces in the formation of individual consciousness, simultaneously playing with Nietzsche's notion of the will to power and Freud's conceptions of the id and the ego. For Deleuze, the truly active forces responsible for the development of conscious thought are essentially unknowable - they are Freud's id, and the only traces of these truly powerful cognitive forces are to be found in the ego - the reactive forces. One is reminded of Anaximander's Aperion, the origin of all things existent, yet itself consisting of a substance unlike any particular existant. Whereas Anaximander's Aperion was meant as an explanation of substance, however, Deleuze, as any good analyst will do, concentrates on the origin of conscious life.
To reiterate, this text is an excellent introduction to Deleuze and the psychoanalysis of power, and any lover of Nietzsche will find Deleuze's playful extension of Nietzschean doctrines enjoyable. But if you're looking for an introduction to Nietzsche's philosophy, then keep looking. The decadent spirit is there, but the historical particulars are not, nor were they meant to be, found.
