The International Journal of Zizek Studies has a special issue, guest edited by Marcus Pound, on Zizek's Theology. Vol. 4, no.4 (2010) contains the following articles (download them by clicking on titles):
Marcus Pound, "Zizek, Milbank and the Broken Middle"
Mads Peter Karlsen, "From a Perverse to a Suffering God - On Slavoj Zizek's Materialist Reading of G.K. Chesterton"
Jayne Svenungsson, "Wrestling with Angels: Or How to Avoid Decisionist Messianic Romances"
Daniel R. Boscaljon, "Zizek's Atheist Theology"
Thomas Lynch, "Religion and Revolution: Slavoj Zizek's Challenge to Liberation Theology"
Dan Webb, "The Unbearable Truth of the Image: Zizek's Iconoclastic Reading of Iconoclasm and Peter Brown's Holy Man"
Adam Kotsko, "Christian Experience Continues: On Zizek's Work Since The Parallax View"
Marcus Pound, "Comic Subjectivity: Zizek and Zupancic's Spiritual Work of Art"
Marika Rose, "A Modest Plea for a Chestertonian Reading of The Monstrosity of Christ"