German listener should check out this facebook-page. They are posting updates regularly for every genre/listener.
Edit, 14.Oct '14: In the latest version of the desktop client, Spotify is promoting audiobooks (at least for german users, don't know how it is in other countries). They openend an official account called "Hörbücher" with playlists full of audibooks ordered by genre as well as weekly recommendations. Fans of audiobooks should definitely check it out!
WOW, i didnt know audiobooks were on spotify! thank you, i have now started following your colaborative playlist there needs to be an easier way to find them, maybe as a genre as i would have never thought to search for them