As a genre writer (I write science fiction, fantasy, and horror, so I can't pin it down much closer than that), I follow a number of feeds that are helpful. These fall into three main categories: excellent genre fiction, markets/writing how-to, and science/futurism.
Podcasts
Fiction
Beneath Ceaseless Skies -
http://www.beneath-ceaseless-skies.com/subscribe.phpClarkesworld -
http://clarkesworldmagazine.com/Escape Pod -
http://escapepod.org/Podcastle -
http://podcastle.org/ Markets/Writing How-to
Odyssey F/SF -
http://www.sff.net/odyssey/podcasts.htmlI Should Be Writing -
http://isbw.murlafferty.com/ Science/Futurism
Future Tense -
http://futuretense.publicradio.org/podcast/feed.phpScience Friday -
http://www.sciencefriday.com/feeds/radio/Radiolab -
http://www.radiolab.org/series/podcasts/ Text
Fiction
Lightspeed -
http://www.lightspeedmagazine.com/ Markets/Writing How-to
Magical Words -
http://magicalwords.net/Nathan Bransford -
http://blog.nathanbransford.com/Dark Markets -
http://darkmarkets.com/ Subset--writers who talk about the craft sometimes and are generally good reading
Scalzi's Whatever -
http://whatever.scalzi.com/Elizabeth Bear -
http://matociquala.livejournal.com/Marissa Lingen -
http://mrissa.livejournal.com/Catherynne M. Valente -
http://yuki-onna.livejournal.com/ Subset--good, free writing/markets newsletters
Writing-World -
http://www.writing-world.com/WritersWeekly -
http://www.writersweekly.com/WritersDigest (for the blog posts) -
http://www.writersdigest.com/GeneralMenu/Duotrope -
http://www.duotrope.com/Ralan -
http://www.ralan.com/ Science/Futurism
Warren Ellis (NSFW on so many levels) -
http://www.warrenellis.com/Scientific American (email newsletter) -
http://www.scientificamerican.com/