ChromeCast has been breaking apps written to push to it as well: http://www.engadget.com/2013/09/21/airplay-mirroring-android...

And honestly, if Google had any intention of having generally open access to it, they would have started with DLNA support, which would have allowed many phones to push to it out of the box. Instead expect it to stay heavily locked down and to only provide good support for getting users on to Chrome and Google Play.