Interesting metadata work going on at LC. Here's a good overview of the The Metadata for Digital Content group.
Consistent and rich metadata are needed in order to improve search of the Library’s collections and provide web services that users have come to expect.
The MDC group members include catalogers, programmers and digital project managers, and represent different service units of the Library concerned with digital content. All are united by the common need for more effective descriptive metadata, which is of increasing importance for the burgeoning amounts of new digital material added to the Library’s website every day. In studying the question of "what are users looking for, and can they find it?," the group determined that the overall quality of the online bibliographic records plays a big part in success or failure. So, how can the records be structured to help users discover relevant resources when they search? [emphasis added]
Jane Mandelbaum, manager in the Library’s Information Technology directorate and a founder of the group, said the group is focusing on "how we build standardized metadata that works across the spectrum of digital objects."
The group has made considerable progress through the creation of a master list of standardized metadata elements used to map existing digital collection records to a single XML metadata scheme. The XML metadata uses the Metadata Object Description Schema.