John Piper and D. A. Carson teamed up on April 23, 2009 to address “The Pastor as Scholar and the Scholar as Pastor.”
(I live-blogged the event, and audio, video, and manuscripts are available.)
Now it’s been updated as a 124-page book:
John Piper and D. A. Carson. The Pastor as Scholar and the Scholar as Pastor: Reflections on Life and Ministry. Edited by Owen Strachan and David Mathis. Wheaton: Crossway, 2011. 
I don’t thank God often enough that I got to spend four years at the feet of each of these men.