I'm rather late on this, but I recently discovered that Rap Genius has started a very cool podcast where they interview rappers, but it's not your typical interview. The interviewer, Shawn Setaro, really is a student of hip-hop and really digs deep into Jean Grae's lyrics, influences and her writing process. He's like Nardwuar without the gimmicks and that's no shot at Narwuar, because I love his work as well. Think of this as Inside The Actors Studio for rap.
You can subscribe to and download the podcast here.