IMS has released its Resource List Interoperability Specification. In the future, I think, we will increasingly see the reading list as a 'portable portal' (a 'portable'?), as you can have services on the contained objects.
The Resource List Interoperability (RLI) specification details how structured meta-data can be exchanged between systems that store and expose resources for the purpose of creating resource lists and those that gather and organize those Resource Lists for educational or training purposes. A typical example of such a resource list is a reading list. [IMS Global Learning Consortium, Inc. - Resource List Interoperability Specification]