For those of you who are into Podcasts, below is the link to the Nature Podcast page:
http://www.nature.com/nature/podcast/index.html
Fingers crossed... I've been caught before posting links to Nature articles that people can't access but I can get this from home, so we should all be right!
They aren't specifically astronomy. These Podcasts cover all sciences, but ther is a healthy smattering of astronomy stuff. The latest one discusses the latest theory of gravitaional resonance / interaction to explain the axial tilt of Jupiter, Saturn, Uranus and Neptune.
Enjoy (I hope),
Al.