Spotify/Rdio-style magic jukebox, and also includes a Pandora-style, algorithm-based radio station. Like Spotify and Rdio (but unlike most of Google’s other services), it costs money — it’s $9.99 a month, or $7.99 if you start a trial before the end of June, and there’s no free option. So, is it worth it?
Also, if you’re reading this from outside the US, you’re also shit out of luck — the service is currently US-only, with no word on when (or if) it might be launching elsewhere. This is par for the course, sadly, and it’s likely that the record labels are to blame, being as they’re apparently not minded (or perhaps not able) to negotiate on a worldwide basis. Whatever the case, the world beyond these shores is left out in the cold again, although if you’re desperate you could probably get it working via a VPN.
The existing Google Music service allowed you to upload up to 20,000 songs to Google’s server and then stream them anywhere, and that option remains, meaning that you can to some extent mitigate one of the problems with streaming services in general: that they’re fine for finding well-known songs, but not so good for tracking down the obscurities that might be lurking in your library. If you have a smallish library, 20,000 songs may well be enough to integrate the whole thing into the subscription service; if not, you can use this functionality to upload the songs that aren’t in Google’s catalog. It’s a pretty nifty feature.
The good news is that you can get a 30-day free trial (although you have to sign up with a credit card to do so), so you can decide for yourself — it may well come down to simple things like UI preference, the two-dollar-a-month savings if you sign up before June 30, the possibility that you’re already well-invested in Google’s ecosystem, or whatever else.