AfroPop worldwide is a real gem of a radio program. They do a great job of exploring African music throughout the Diaspora. Their shows are well researched, timely, and the music is always interesting. Often the recordings of music (both from the field and studio) are interspersed with interviews with academics as well as musicians themselves.
I would like to hear a few shows that tie in African musical elements from different parts of the world, instead of staying specifically in one place. Also, the longer the podcasts the better!