JISC has released In from the Cold: An Assessment of the Scope of 'Orphan Works' and Its Impact on the Delivery of Services to the Public.
Here's an excerpt from the announcement:
The scale and impact of Orphan Works across the public sector confirms that the presence of Orphan Works is in essence locking up culture and other public sector content and preventing organisations from serving the public interest. Works of little and/or variable commercial value but high academic and cultural significance are languishing unused. Access to an immense amount of this material, essential for education and scholarship, is consequently badly constrained, whilst scarce public sector resources are being used up on complex and unreliable 'due diligence' compliance. Without any kind of UK or European Union-wide legal certainty, there will remain a major risk for all users of Orphan Works. The quantity of Orphan Works and their impact is only accelerating as content is being created and digitised without adherence to any single internationally recognised standard for capturing provenance information.
The data and anecdotal feedback suggests that many public sector organisations are themselves unsure as to the extent of the problem, and that staff awareness and understanding are often limited.
There are also suggestions that often works are selected for digitisation based on the fact that they do not pose any copyright issues, thus creating a black hole of 20th century content. These issues stress the need for an informed and skilled public sector to deal with all the issues associated with copyright-related materials, the necessity for access to resources to deal with Orphan Works, and an informed and proportionate understanding of the nature of the risks associated with the use of these works.