We all know what that is.
So what is one to do? Here are some of my tests for interoperability solutions: Does your vendor know more than just the letters, H-L-7, I-H-E, or F-H-I-R? Ask them if they've ever sent someone to a connectathon or and IHE or HL7 meeting. See if they even know and can list some HL7 standards or profiles. Do they know that a CDD or CCDA is based on CDA and that is based on HL7 version 3 and X-M-L? Can they unparse these acronyms, or do they have someone in there booth that can?
If not, be careful, they might just be full of it, and you might be stepping in it.
If you want to see interoperability that works, come on down to the Interoperability Showcase, where you can see products from different and competing vendors working together. You won't see that anywhere else on the show floor