Anyone who uses Google Reader will know that it's very bare and it has a lot of lists. There's no shame in that though, as most people's RSS feeds are cluttered enough without the reader itself adding to things. Google Play is just as clutter-free as Reader, but it does away with the lists. Displaying one post at a time on a black backdrop, the pictures pop out and everything is a lot more aesthetically pleasing.
However, Play is not just an upgraded version of reader. Google is targeting the casual Web browser and by clicking the like or share buttons, Google will bring you more posts that it thinks you'll like based on your history. You can also choose to only see posts from certain categories. If you've ever used Stumble Upon, you'll know exactly how this concept is supposed to work.
Reader Play uses the same technology as the "Recommended Items" feed in Google Reader. If you sign in, Reader Play will offer you a more personal experience, offering you items that people you’re following have shared in Google Reader, as well as items similar to ones you’ve previously liked, starred, or shared.
Check it out (Google.com/reader/play) and let us know what you think!