I don't know if this is true. Epic has already implemented large parts of FHIR and Cerner has also committed to it as well. You can even play around with Epic's implementation on FHIR here: http://open.epic.com/Interface/FHIR. I'll admit. I was shocked when I found out it connected to a real Interconnect engine.

This makes a lot of sense. IHE profiles and CCDAs are suboptimal ways in 2015 to transfer data between HIEs and Epic/Cerner/Allscripts along with every other EHR vendor either sell them or need to connect with them. It would behoove them to embrace this support in the same way it behooved hospitals to embrace HL7v2 in 1990: it saves them alot of work and money.

Of course, this doesn't help the average patient or app developer. How users will interact with these APIs and whether or not hospitals will have a standard and easy way to open them up is still yet to be seen. I imagine there will still be some work involved there, but I'm optimistic for the future.