During the Berlin Sprint Holger was interviewed by Tim Pritlove for Tim's Podcast "Chaosradio Express". The whole thing is in German, so only interesting to German-speakers. The PyPy episode can be found here. The interview is touching on a lot of topics, starting with a fairly general intro about what Python is and why it is interesting and then moving to explaining and discussing PyPy. The bit about PyPy starts after about 45 minutes. There is also a comment page about the episode.