At Speak Up, Armin Vit has a post about Ellen Lupton's revived Design Writing Research project... Among other things, there is an Archive of articles and interviews. Some of the interviews are previously unpublished, such as the one with Tobias Frere-Jones, or unedited versions of published ones, like the Jonathan Hoefler interview. Both of these interviews date from the mid-1990s and make for some interesting reading.