Seeing the topic "Books never to be finished" my first thought was books announced for future publication but which have never seen the light of day - for whatever reason.

At least 15 years ago, Joni Mitchell's Memoirs/autobiography was announced as a forthcoming title. It's still unpublished (unwritten?),despite occasional announcements on progress. I understand how she could present a problem on the litigation front, though...

Any more examples that the massive can think of - not necessarily music-related?