Federating purl.org ?
I suggested a while back that PURLs have become quite important, at least for some aspects of the Web (particularly Linked Data as it happens), and that the current service at purl.org may therefore represent something of a single point of failure.
A PURL Federation is proposed which will consist of multiple independently-operated PURL servers, each of which have their own DNS hostnames, name their PURLs using their own authority (different from the hostname) and mirror other PURLs in the federation. The authorities will be "outsourced" to a dynamic DNS service that will resolve to proxies for all authorities of the PURLs in the federation. The attached image illustrates and summarizes the proposed architecture.
Caching proxies are inserted between the client and federation members. The dynamic DNS service responds to any request with an IP address of a proxy. The proxy attempts to contact the primary PURL member via its alternative DNS name to fulfill the request and caches the response for future requests. In the case where the primary PURL member is not responsive, the proxy attempts to contact another host in the federation until it succeeds. Thus, most traffic for a given PURL authority continues to flow to the primary PURL member for that authority and not other members of the federation.
I don't know what is planned in this space, and I may not have read the architecture closely enough, but it seems to me that there is now a significant opportunity for OCLC to work with a small number of national libraries (the British Library, The Library of Congress and the National Library of Australia spring to mind as a usefully geographically-dispersed set) to federate the current service at purl.org ?