I am sure that the future reviewers of the book will point it out, but the first three chapters (constituting “The Drink Before” = Part One) are supposedly preparing us for the encounter with Hegel and Lacan (with a final section – “The Cigarette After” = Part Four). Having finished Part One I am not entirely sure what is about to happen in Parts Two and Three. So if it is indeed a “drink before,” than it is entirely unclear what is to follow. I think there is always a general discrepancy in Žižek between the announced structure of the book and the actual content, but in this case we are witnessing a grandiose structure basically coming to nothing, perhaps on purpose, but I doubt it. So we are getting ready for something with a drink – obviously sex, but with who? Hegel or Lacan? Both? Part Three is Hegel, Part Four is Lacan – so we are having sex with them one after another? The reader than is a kind of prostitute, prepared by the pimp (Žižek) with a “drink before” (and maybe some drugs to dull the obvious humiliation) for the encounter with two of his most important johns.
Here is my intuitive evaluation of Part One’s actual content: it is an intellectual diary. Žižek reads an interesting book, he makes some notes about it, he puts it in the book. Perhaps he later rearranges the parts about various books or ideas, but perhaps even that piece is missing. It is not bad in itself, I think. In fact it seems that Žižek’s appeal might be found in this very raw status of his ideas – anyone can just pick them up and run with them. However, it makes for a rather challenging read since it’s not clear where he is going with all of this and why. I think one generally needs to be very sympathetic to Žižek’s project (if such exists) in order to enjoy his ruminations. However, when one comes across some objectionable stuff, then it is harder to just sit there and take it.
Chapter Four apparently promises to get to the “thing itself” – Hegel. The usual question – can one be a Hegelian today? – is approached via Gérard Lebrun’s last book on Hegel (we’ve mentioned Lebrun here on PE before – doesn’t seem like anything was ever translated into English, perhaps the Žižek bump will do the trick). But here is an objectionable sort of statement that might stop some in their tracks:
Most ridiculous among such critical refutations is, of course, the standard Marxist-evolutionist idea that there is a contradiction between Hegel’s dialectical method—which demonstrates how every fixed determination is swept away by the movement of negativity, how every determinate shape finds its truth in its annihilation—and Hegel’s system: if the destiny of everything is to pass away in the eternal movement of self-sublation, does the same not hold for the system itself? Is not Hegel’s own system a temporary, historically relative formation which will be overcome by the progress of knowledge? Anyone who finds such a refutation convincing is not to be taken seriously as a reader of Hegel. 
Now, see here Comrade Žižek, I don’t think there is anything unconvincing about such an interpretation and there is certainly no reason to reject those who think it is legitimate in some gesture of dismissal (without any real argument). What this and similar statements made in the book seem to say is “Unless you buy into Hegel’s own self-descriptions, you are not going to be able to understand the argument here” – fair enough. However, the promised theme of the book is “dialectical materialism” and since Žižek already mentioned Stalin, it is precisely this interpretation of Hegel that was prevalent in the (middle) Soviet philosophical period, starting at around 1930 and until Stalin’s death. Hegel was perceived to be the direct predecessor of Marx and his method was solid while his system was “idealist” and rotten. Of course this is not a “serious” reading of Hegel, but Žižek just lost anyone who will be interested in seeing how he disproves (if he ever gets to it) this position, the position that is basically the foundation of the entire field of “Soviet Hegelianism” (if such exists) or “diamat” (Sovietese for “dialectical materialism”).
So how to move beyond Hegel? Lebrun’s answer is one option. I’m not very interested in this so I’m skipping this part. Well, perhaps for this bit:
The obverse of Hegel’s “nihilism” (all finite/determinate forms of life reach their “truth” in their self-overcoming) is its apparent opposite: in continuity with the Platonic metaphysical tradition, he is not ready to give negativity full rein, that is, his dialectics is ultimately an effort to “normalize” the excess of negativity. 
So Plato and Hegel aren’t really that different. This is of course a simplistic way of putting it. But clearly the work of “negativity” in Hegel is an interesting theme in and of itself. Negativity moves everything, says more or less traditional interpretation of Hegel. Lebrun (and can only assume Žižek himself, although he simply restates Lebrun up to this point) objects to this interpretation because ‘Hegel’s dialectics “in no way involves the recognition of the irresistible force of becoming, the epopee of a flux which takes everything with it…” How so? Isn’t Hegel’s dialectics precisely all about the becoming, the instability of any sort of being/nothing? Explain, please!
This notion that Hegelian dialectics preaches a kind of “mobilism,” Žižek (or Lebrun, not clear at this point) argues, is mistaken – but it is widely known due to its popularization by Marxists:
The most popular form of “mobilism” is the traditional view of Hegel as the philosopher of “eternal struggle,” popularized by Marxists from Engels to Stalin and Mao: the well-known “dialectical” notion of life as an eternal conflict between reaction and progress, old and new, past and future. This belligerent view, which advocates our engagement on the “progressive” side, is totally foreign to Hegel, for whom “taking sides” as such is illusory (since it is by definition unilateral). 
I think it is safe to note that Žižek is careful not to conflate Marx and Marxists. The issue here is then whether there is a continuity between Engels (Dialectics of Nature) and Stalinist dialects (that Žižek discusses later in the book – I looked it up). Stalin’s dialectics (from The Short Course) isn’t exactly the same as “diamat” (but close enough to confuse people). It is important to remember, however, that Stalinist dialectics is a result of a good decade of philosophical discussions in the Soviet Union (from around 1920 to 1929). Žižek’s not really into this sort of careful historical analysis – but it is an essential component of any discussion of “dialectical materialism” (here standing for Soviet philosophy, not the pre-Soviet versions found, say, in Plekhanov or Dietzgen).
But how the Stalinist position inconsistent with Hegelian position? Žižek points out that Hegelian dialectics isn’t a form of “mobilism” in that it does not propose some sort of reconciliation, some sort of closure:
The Marxist reproach that, instead of transforming reality, Hegel merely proposes a new interpretation of it, thus in a way misses the point—it is knocking on an open door, since, for Hegel, in order to pass from alienation to reconciliation, we do not have to change reality, but rather the way we perceive and relate to it. 
But the Marxist reproach then does not miss the point – sure, Hegel does not fail at what he does not aim to do (according to Žižek), but he fails nonetheless if one takes the Marxist position as somehow referring to the actual state of affairs of alienation and so on. If Hegel does cover up the “class antagonisms” in his philosophical system but does so using a “method” that can be useful (if extracted), then Marxist critique in this sense goes beyond Hegel (or claim to do so) and thus Marxists aren’t Hegelian but are nonetheless indebted to Hegel. This is basically the position of Soviet readers of Hegel (and Marx). On the one hand, he is the pinnacle of idealism (and nothing stings more than an accusation of idealism, both before and after 1917 discussions). On the other hand, there is a valuable (“dialectical”) core to Hegel that can allegedly be used in the construction of the new kind of materialism.
Then there follows a rather startling conclusion: Hegel’s point, Žižek argues, is that there is no resolution of the conflict, no reconciliation, because there is nothing to reconcile, or there was never any real struggle, only an illusory contradiction:
This is how Hegelian reconciliation works—not as a positive gesture of resolving or overcoming the conflict, but as a retroactive insight into how there never really was a serious conflict, how the two opponents were always on the same side (a little bit like the reconciliation between Figaro and Marcellina in The Marriage of Figaro, where they are brought together by the realization that they are mother and son). [204-205]
This example from Figaro is not really as good as Žižek thinks it is, but perhaps this merits another post as this one is rather long already.