I recently finished reading the the Interim Report of the Blue Ribbon Task Force on Sustainable Digital Preservation and Access entitled "Sustaining the Digital Investment: Issues and Challenges of Economically Sustainable Digital Preservation." [PDF].
The report is very readable and engaging and really focuses on the key topic of sustainability. The authors make the point that while we all agree that digitized materials are important for scholarship, we don't yet have a coherent plan for how to preserve these digital resources. I like the fact that the report doesn't shy away from the economic realities of this issue -- to preserve digital resources, someone has to pay for them. But who? And how? The report is a good take on helping to answer these questions. My thanks go to Fran Berman and the rest of the Blue Ribbon Task Force who wrote this report and to NSF, Mellon, and the other organizations who funded it.