The combined YouTube Music Key and Google Play Music Key is expected to sell for $9.99 per month. That's the same price as All Access runs for now.
The resulting service provided here is one that is ultimately unparalleled in the media streaming world right now. Google is effectively providing a one stop shop for all of our musical desires. No longer will we have to go to Play Music to listen to tunes, then kill it off and open up YouTube to be able to catch the video for that same artist we were just listening too.