Missing Spotify is killer for me, it's actually tempting me to try Apple Music since I anticipate having an Apple TV connected to my other TVs in the house sooner or later. It doesn't even seem to be an issue of Apple blocking Spotify to try and steer users to AM, Spotify just hasn't created an app yet (no idea if it would get approved though). Seems like a strategic mistake on Spotify's part.
I've seen this issue for several apps (Spotify, Amazon Video, etc.), and I always just shrug it off. You can use both with an AppleTV, but the application has to be installed on a secondary device like an iPhone and then streamed via Airplay. Both of the explicitly mentioned applications work great, with that one exception of not having a native application on the device.
