The Secure Public Data Repository?

jducoeur writes "So Hailstorm has died an unlamented death. But the demand for the idea of an information repository isn't going to go away -- users demand convenience, and this would be convenient. So here's a timely question looking for wild speculation: how would a truly secure, public data repository work? How would your data be stored? Would it be centralized or distributed? How would you grant access to specific elements within it? What would the business case for running such an archive be? Maybe if we can come up with a good design now, we can head off the next inevitable bad one..."