I have the same question.  My son listened to a few episodes in the middle of MVP and is hooked, and I'd like to start him at the beginning of the series... but only if I can find a young adult audio version.  The iTunes podcast of The Rookie carries an explicit tag, but I'd be willing to purchase the audiobook if there were a clean version.

I can't recall where it is in the list of projects, but I seem to remember The FDO commenting on this. I believe he said it is in the project pipeline. 

We are working on this. It's on the docket to be recorded after I finish PANDEMIC. So, all-ages ROOKIE should be out in 2013.