Besides new family-friendly and kid-friendly efforts on search and discovery in the Play Store, Google announced during its keynote today that Play Store search will be getting smarter overall.
Specifically, Google wants to more effectively surface apps when users search for vague or topical queries. The example given in the screenshot above shows the user searching for "shopping" apps. The Play Store then returns, of course, shopping apps. But those apps are then categorized intelligently into different sub-genres like Fashion and Coupons.
This may seem like a small tweak to most users, but - if Google is right - it will help introduce users to the right app when the user is not sure exactly what they're looking for, which is a good step in helping along discoverability in the Play Store as a whole.