The Authors Alliance has released Understanding Rights Reversion: When, Why, & How to Regain Copyright and Make Your Book More Available.
Here's an excerpt from the announcement:
This guide is the product of extensive outreach to the publishing industry. In the process, we interviewed authors, publishers, and literary agents, ranging from a CEO of a major publishing house to contracts and rights managers of trade and academic presses, editorial assistants, novelists, and academic authors.
We were happily surprised by the consistency of publishers' responses: across the board, publishers told us that they want to work together with their authors and that they are often willing to give authors their rights back if its in the books' best interests.