Zizek is one of a number of contemporary continental philosophers (Agamben, Badiou, maybe Spivak etc) that feels the post-structuralist rupture with modernity is perhaps overstated, and that political liberation is a realistic, achievable project. Obviously a philosophy after Derrida, Foucault, Deleuze et al won't ever be the same, so this is not suggest that group has dismissed them altogether (or of course that these post-moderns didn't believe in some sort of liberatory project), but rather that they believe in the strategic application of essentialisms and universalities in the attack on existent social orders. Zizek specific is firmly grounded in Marx (Hegel) and psychoanalysis, so while quite the majority of humanities people at my school are still talking about foucauldian discourse analysis, Zizek is going back to gramsci and Lacan and talking about ideology, the real etc. His foundation in Marx makes him a staunch critic of capitalism, but hes not boring as fuck and even from a more anti-civ perspective I happen to share something of an affinity with him. The film Zizek is funny as shit. I'm not a zizek scholar or really that engaged with contiental philosohpy, but I guess, brief, he is offering some people an alternative to what is thought of as a trend towards ivory tower, relativist critiques.