I just stumbled across a very nice resource – Fast Forward: Contemporary Science Fiction is a television show based in Arlington, VA. They have interviewed a number of science fiction authors, and they have archives going back to 2003 so you can listen to (or watch – each interview is available in MP3 audio format or compressed video format) at your leisure.
The following interviews are currently available: Orson Scott Card, Lois McMaster Bujold, Connie Willis, Neil Gaiman, Patricia Wrede, Elizabeth Massie, Laura Anne Gilman, Susanna Clarke, Jasper Fforde, China Miéville, Cortney Skinner, Kim Stanley Robinson, Bruce Sterling, William Gibson, Tamora Pierce, Nalo Hopkinson, Jack Williamson, Terry Pratchett, Karl Kofoed, Margaret Weis, Laurell K. Hamilton, Garth Nix, Roger MacBride Allen, Donna Andrews, Catherine Asaro, Robert Jordan, Will Ludwigsen, and Mindy Klasky.