The first episode of Anger, Sadness & Envy, the official podcast of Bungie fansite Rampancy.net, covers the first two levels of Halo 3: Arrival and Sierra 117.
We're working on getting this submitted into the iTunes podcast directory, but until then, you can manually subscribe in iTunes by pulling down the Advanced menu, choosing the "Subscribe to podcast" item, and entering one of these two URLs:
http://rampancy.net/podcast/angersadnessenvy
http://feeds.feedburner.com/AngerSadnessEnvy
UPDATE: I've successfully submitted the 'cast to iTunes now, but it's not showing up yet in searches or in the Video Games category where it should. Hopefully it will soon.
UPDATE: The podcast is in iTunes now. It doesn't seem to be showing up when you search or browse yet, but this link should bring iTunes straight to it:
http://phobos.apple.com/WebObjects/MZStore.woa/wa/viewPodcast?id=266991411