Dear Maintainer, I've updated my libechonest PPA. I've cleaned up the multiarch support and added a transitional package for libechonest2.1. I've also build those packages under debian sid locally. And so you should be able to adopt my debian files.
https://launchpad.net/~justin-time/+archive/ubuntu/libechonest/+packages I would be very happy to work together with you to push libechonest2.3 as Qt4 and Qt5 build into the debian sources. Kindly regards, Stefan Ahlers