The music app and iTunes on Mac just feel a bit outdated, like they're not products of the current music-listening age.
Apple will hopefully combine Beats into iTunes/Music app into a seamless experience and really compete with the likes of Spotify and Rdio.
The Music/iPod app were groundbreaking in 2007 but it's barely changed since then other than some visual refreshes with iOS7. I want to discover other music I might like, and not by having to go into the separate and equally clunky iTunes app.
I want to see what my friends are listening to and what's recommended. I want curated playlists, radio, streaming music, all the bells and whistles I come to expect from a modern music service.
I don't want a cloud 'locker' for my music aka iTunes Match.