Installation is simple. Just download & install it.
The most notable and immediately apparent new feature is the long overdue ability to remove apps you've previously downloaded from the All Apps list. If you like to try a lot of apps, that list is likely very cluttered. With the new Google Play, you can trim it to your heart's content.
Update #1: You can multi-select by long-pressing any app in the list and then tapping more apps, then delete them all in one go (added 2 new screenshots demonstrating it).
Update #2: The new Play Store now keeps track of your location in lists, including My Apps and All Apps, so when you click into an app and back, it drops you into the same spot. I had variable luck with this, and it didn't seem to work in All Apps at first, but I just reproduced it on both the EVO LTE and the Nexus 7. Brilliant.
Update #3: The notification icon that shows up when you have app updates has changed, and notifications are now expandable. I've added more screenshots showing the differences.
Update #4: The notification icon after installing an app now shows the app icon instead of something generic.
The size of the Play Store APK actually went down, so Google must have trimmed some extra fat. We're still digging through everything - in the meantime, check out the screenshots and grab the new version from my Ubuntu One
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