In March 2012, previous users of the Android Market suddenly found themselves with a new update, as did Google Music and Google Books users. Google Play is essentially a rebranding of the previous Android Market. Google's new name choice is a little interesting, but the Android Market was clearly in need of some sort of revamping. It had grown far beyond the original scope and may need room for future expansion.
The Case for Change
The market previously known as Android Market used to be as simple as that. An Android app store. When it was the only Android app store, this was pretty straightforward. Along comes Amazon, Sony, Samsung, and just about every single phone and Android tablet maker with their own, separate app stores. Now it's starting to get confusing which Android app store you mean, especially when people get confused and call the Android Market things like "the Google Market" or "the Android App Store."
The Android Market not only had potential market confusion with all the other app stores, but Google kept adding onto the thing with new features. You can use the Market to buy Google Books. You can purchase and play Google Music. There are video rentals on some devices as well. Not only will most of the new features work on Android, they'll work on Chromebooks, laptop Web browsers, and iPads. That means Google is trying to get you to surf your Macbook to a site labeled "Android," to buy a book or rent a video, and that's just confusing.
Now all your Google-facilitated content purchases are through one portal, Google Play. I've heard plenty of grumbling at the new name. The word "play" implies that the store now only sells games. The logo points to a different reason. The new Google Play logo is a triangle in the familiar "play" button on videos. I'm still not sure how a book "plays," but I can see this as a combination the content consumption definition of "play" and being playful in exploring what content is available.
Google Play still sells Android apps, but now they're available through the "apps and games" section of the Play Store. Yes, that was as awkward to type as it was to read. I'm sure we'll all develop shorthand like "Play apps" or something similar.
The old Google Music logo has been retired, and mobile users received a new logo with a slightly different pair of headphones. In fact, the Web version of the product has been entirely consumed by Google Play. However, the Play Music store still works the same way as the old standalone Google Music product. The player still works the same way, only you find it under the My Music section of Google Play. The majority of the changes here are cosmetic. However, Google does seem to be making renewed efforts to promote music sales. That's good news for consumers who want cheap tunes and frequent giveaways.
Google Books used to be confusingly divided between book search and eBook purchases. That's not entirely gone, but it has been slightly improved. The old Google eBook Store is now just a section of Google Play. Your library is still there. You're still free to download your books and transfer them to your Kindle or other reader. Your library is now part of the My Library section of Google Play.
Movies are still a little confusing. The YouTube team and the Google Play teams seem to be sending a mixed message. Your movie rentals are available both through Google Play and through YouTube. If you're playing a movie on a mobile device - say you're getting ready to fly somewhere and want to download a movie for watching on the plane, use Google Play. If you're watching from a computer or a device that supports YouTube but not Android, use YouTube. I foresee all sorts of user confusion until they get this one ironed out.
The Future of Play
Since Google now has a market for putting all shopping content into one area, the sky is the limit. They could go after Amazon and start putting physical goods there as well, although it's unlikely they'd want to go beyond Android devices at this point. It would certainly give them a platform to launch more consumer electronics.