[programminggeek]

I think that assumes some serious hand waving on the part of both your app and the api's. Assuming that just pointing at the root of another API is going to mean your app will magically behave properly using both API's is making a lot of assumptions either in your app about how the API's work. For example, say one API calls a delete call "delete", another calls it "remove", another calls it "obliterate", and at the same time one API takes an id on that method as input, another takes an email address, another takes a username. In that scenario your app might be written to remove something based off an id and when you switch API's the new one expects you to obliterate based on username. Hypermedia doesn't save you there.

I'm all for pluggable protocols and standards, but Hypermedia links in your API don't magically get you there. They might help, but no more than a standard spec with standard URL patterns would.