Amazon.de is listing a future audio version of Epic in German, on five CDs. The voice artists appear to be Gisela Trowe, Andreas Fröhlich and Woody Mues. Both Gisela Trowe (German wikipedia entry) and Andreas Fröhlich (German wikipedia entry) are experienced voice actors. Andreas Fröhlich dubbed Gollum in the German language version of Lord of the Rings.
Updated: to add cover picture