I found the latest version of Google Play Music to have really really bad wakelock, like my phone is virtually never in deep sleep mode. I got it uninstalled and battery life is "normal" now. I mean "normal", as in, not any different from ICS.
Google Now wakes my phone often to fetch network location, but that doesn't tax my battery too badly
Google Now wakes my phone often to fetch network location, but that doesn't tax my battery too badly