On June 15, 2011, George Talusan, a Kobo developer Intern posted on this thread a link to a Linux build of Kobo Desktop:
http://dl.dropbox.com/u/2183775/kobo-desktop.deb . This URL has been mentioned in a number of messages on this thread since. However, when I try to download it now, I get a 404 Not Found error. Does anyone know what happened to it? Is there a newer Linux build of Kobo Desktop anywhere?