They're more SFF commentary/review podcasts than writing ones, but I listen to the Coode Street Podcast, Galactic Suburbia and The Writer and the Critic regularly. All Australian in origin, though the first is really an Aus/US coproduction.
Blogs by Nina Allan, Abigail Nussbaum, Ian Sales and Jonathan McCalmont, all SFF-based. Of those four, Allan and Sales (vested interest alert: I know them both personally) are award-winning fiction writers.
Outside writing I also listen to film-based podcasts: the Kermode and Mayo Film Show from BBC Radio 5 Live, the podcasts at The Digital Fix (second vested interest alert: I have taken part in some of them) and the Guardian Film Show (actually a videocast).