ETA: Removed author death restrictions

I was reading reviews and comments on Patrick Rothfuss's Doors of Stone, and thought of those I had waited impatiently for in a similar fashion.

This list is for books with large differences between the original/anticipated publication date and when the book was actually released, including informal author announcements.

This list is for:

1) Books with a significant delay in publishing versus announcement. I don't want to be too stringent with minimum delays, but at least two years, and I prefer three+.
They may be forthcoming or already released.
They may be from any time period.
They may be from any genre and on any topic. Fiction, non-fiction, academic, picture books, comic books are all okay.
Any reason for delay is acceptable.

Other acceptable materials:

2) Audiobook versions of printed books (including e-books)

3) Text versions of audiobook-only materials

4) Publications that are postponed indefinitely, although please note this in the "Why I added this book" area.

ETA:
5) Book series dropped by one publisher IF they were later picked up by another (including if a publisher went under).
These do not need announced release dates like the others provided the series was meant to continue (e.g. it had a ginormous cliffhanger). List the book following the gap.

This list is NOT for:

1) Forthcoming books you are excited about, unless they fit the above criteria.

2) Books that did not/do not have a tentative schedule. It needn't be formal. An author comment along the line of "expect it in the next two years/in August 20XX" is acceptable.
A comment such as "I'd like to write about XYZ at some point" is not.

3) Books MEANT to be published posthumously.

4) Books in a series announced with no descriptors. There's leeway for stuff like the aforementioned "Doors of Stone" in a definite trilogy, but no placeholders like "untitled series book, March 2019".

5) Delays BECAUSE of a forthcoming book. Example (as of this writing) is GRRM's "Dream of Spring". Delays after are fine.

6) E-book versus printed book differences