It is and its on our list (actually its on a git branch). Just didn't make it across the line for v1.
As a stop gap we have this in our FAQ:
Radio currently doesn't directly support Airplay.
However, if you'd really like to stream Radio via Airplay, here is a trick you can use:
Hold the Alt-key and click on the Volume icon in the menu bar, a menu will appear showing any available Airplay device. Select your Airplay device and all your sounds will play over Airplay.
As a stop gap we have this in our FAQ:
Radio currently doesn't directly support Airplay.
However, if you'd really like to stream Radio via Airplay, here is a trick you can use:
Hold the Alt-key and click on the Volume icon in the menu bar, a menu will appear showing any available Airplay device. Select your Airplay device and all your sounds will play over Airplay.