Most RHIO's have been morphed into Health Information Exchanges (or HIE's). For example, there were a couple RHIO's in Mississippi, that as a result of Hurricane Katrina, is now part of the Mississippi Coastal Health Information Exchange (MSCHIE). You can easily google it for more information.
Why important? One, think of Hurricane Katrina and the amount of loss medical information that just "blew up" in the storm. If I was in New Orleans and got relocated to Jackson, MS, none of my personal health information is available. However, if there was an HIE, and my records were online with the HIE, I could notify my doctor in Jackson and he could obtain electronic copies of my records, hence providing better care to me. Second, HIE's will aggregate data for population health! HIE's, for example, will be able to notify the CDC if there is an outbreak of West Nile Flu by the number of diagnoses reported by each HIE member hospital. Separately they may not know about this outbreak, but when looking at all the hospitals in the area (which the HIE will do), there is an outbreak. Last, besides preventing lost records, and reporting population health concerns, the HIE can contain other services to independent physicians that can't afford an EHR. For example, an HIE can provide the ONC's Direct Messaging product allowing independent physicians to send patient information to each other via the messaging product. Additional services, like electronic prescribing are also available.