How would that work? The existing provider would have to provide an API or export feature, or else you'd be back to re-entering shit by hand. My problem is that most (if not all) of these existing systems seem to lack any kind of API or ability to dump data in a machine readable format. :-(
They are using the view, download and transmit aspects of meaningful use 2. So they either scrape the portal or parse the downloaded file. The downloaded file is often a variant of c-CDa. However each portal can be different so I assume they are doing the epic and cerner (large dominant players) first.