I have been doing a little background research on the US Health Information Exchanges(HIE).
In doing that I came upon some presentations and videos that explain how at least one vendor (apparently presently the most successful over there) is supporting the HIE vision.
They can be viewed here:
If we could get to this level we would transform Health Services in Australia I reckon.
I know these are advertising videos, but there is real value in seeing what they can now deliver.
I am also aware other providers can do similar things. This is just a well presented example that shows where things are over there.
Note the lack of need for a National HI Service to do all this!