There has never been a time when so much is being written about sport and Christianity.  2012 saw the publication of three major books:

Sports and Christianity (Historical and Contemporary Perspectives), Nick J Watson and Andrew Parker, New York, Routledge, 2012

Catholic perspectives on sports (From medieval to modern times), Patrick Kelly, New York / Mahwah, NJ Paulist Press, 2012

Sport and Christianity (A sign of the times in the light of faith), Edited by Kevin Lixey, L.C., Christoph Hubenthal, Dietmar Mieth, and Norbert Muller Washington, D.C. The Catholic University of America Press, 2012

As well as those there were two journals which devoted an entire issue to sport:

Studies in Christian Ethics, Volume 25, Number 1, February 2012

Practical Theology, Volume 5.2, 2012.

In addition two major books are expected to be published later this year or early next year:

The Games People Play: theology, religion and sport, Robert Ellis, Eugene, OR: Wipf & Stock,

Brief Theology of Sport, Lincoln Harvey, London: SCM Press, forthcoming

See reviews of the top three at http://www.veritesport.org