"We aren't planning any immediate changes to Songza, so it will continue to work like usual for existing users. Over the coming months, we'll explore ways to bring what you love about Songza to Google Play Music. We'll also look for opportunities to bring their great work to the music experience on YouTube and other Google products. In the meantime, check out their service on Android or iOS to find a playlist for any mood you're in — whether you're feeling a little mellow or a lot funky," suggests Google.
Songza's site has a page about the acquisition: "Today, we're thrilled to announce that we're becoming part of Google. We can't think of a better company to join in our quest to provide the perfect soundtrack for everything you do. No immediate changes to Songza are planned, other than making it faster, smarter, and even more fun to use."
There's also a Googley logo:
Curated playlists are very popular nowadays. That's the main feature of the Beats Music service recently acquired by Apple.
"Stating that its playlists are made by music experts, the service recommends various playlists based on time of day and mood or activity. Songza offers playlists for activities such as waking up, working out, commuting, concentrating, unwinding, entertaining, and sleeping. Users can vote songs up or down, and the service will adapt to the user's personal music preferences." (Wikipedia)
The New York Times reports that "Google paid more than $39 million for Songza".