Both, clinical repository and exchange are challenges in new conceptions around TI in healthcare.
I know how the RIM can aid (or inspire) some ideas for the clinical repository, EHR-S show us the functional aspects of the system, and why not, talk about openehr, CTS, MPI, RBAC and other necessary parts (inside HL7).
About exchange CCD,CRS or e-ms clinical document summary are real solutions for exchanging clinical summary between rhio or systems.
But what about use the concept in ccd or crs to manage the clinical repository. Think about a RHIO that has (conceptually speaking) a crs document that grows every day with added or changed clinical information. Only a few xml tranformations and you will have diferents views of a Patient Record (one doctor , one diferent view in a extreme world) and according with patient consent too!!!!.
I'm just digesting page 40 of part 2 of CHF and I know that it is a good knowledge to use.