This would consist of the following two events:

1. A high-profile workshop on open bibliographic data. This would bring together high-level stakeholders from a variety of libraries around the world (with a focus on Europe). The first half of the day would be presentations from prominent libraries that have opened up (some of) their meta data, e.g. the British Library, Cambridge University Library, CERN, and so on. The second half of the day would be presentations on applications and services using bibliographic data in compelling new ways, as well as on the future of bibliographic data. There might also be things like focus discussion, as well as brief overviews on how to open up library catalogue data (legally, technically, and so on).
2. A hands on workshop/hackday on open bibliographic data. This would be a satellite event aimed at those who are building things with bibliographic data, exposing it in new ways, working on related technical infrastructure, and so on. There could also be strands for non-technical participants, e.g. to produce documentation, to make a film, to brainstorm about new applications and services, etc.