I am with Nigel on desiring native Airplay support like the new speakers. I would even be willing to pay extra, on top of my license, for the feature!

I believe there is a way to setup a system to request a 'promotion' code for the app store that could let you verify licenses, and then send a code to someone with a valid license, to allow a free download of an otherwise paid app. Would be some extra work on both ends, but would give the desired effect.