The Echo Nest was just purchased by Spotify. It is hard to predict how it will change in terms of future availability to 3rd party software and license terms. Already rdio has aborted its use of The Echo Nest out of fear that its customer's usage data will leak into Spotify's hands.
My
pscriptor tool has an echoprint-based AcousticFingerprint plugin (which started as a proof-of-concept, but is functional now). I plan on doing more with The Echo Nest, as there are some nice cross-service tools available (e.g.
Project Rosetta Stone and multiple ID spaces).
I don't speak for JRiver, and have no idea if they are interested in pursuing any of the features The Echo Nest can provide. There hasn't been much interest in connecting to external services such as this, so this might best be left to 3rd party development.
