I recently finished Matthew Sharpe's new study of Zizek's Politics. The first thing to note is just how clear the analysis was on Zizek's corpus. Job well done! I have read a lot of Zizek introductions and I have to say that next to Kotsko's (which I frequently return to) this is a good place to start if you are interested in this particular theorist.
The crux of the book is the idea that there are two theorists in Zizek: 1) Zizek as the Radical Democrat (which could also be called the early Zizek up into his works on Schelling; here Zizek is more concerned with the Symbolic) and 2) Zizek as the Revolutionary/Vanguard (which is post Schelling and his so-called Christian works; here Zizek leaps into the Real). The current Zizek is the Zizek2 even though Zizek1 has not entirely gone away. Sharpe beleives that there is a turn with Shelling into a much more pessimistic turn to Zizek's overall work. Sharpe ultimately criticizes Zizek2 for basically becoming a closet admirer of Hobbes/Schmitt.
I have been wrestling with this thesis for the last couple of weeks especially as I have been reading some Derrida lately. I wonder, as my brother pointed out, that this pessimism that offends people is the deferment of easy solutions, or real concrete acts of justice, or of the real ugliness that is out there in the world... I really do think that the "theology" that theorists like Zizek have been dealing with lately (as opposed to the "impossible god") is worth something that can perhaps awaken believers from their dogmatic slumbers. So reading Barth (like always) and Derrida with Zizek in the background continues to open up new dimensions for me; at the most part, it is a comfortable unsettling that he brings.