Preview at WWDC likely in June, followed by September launch.
Apple to Clean Up App Store, Eliminate Outdated and Non-Functional Apps
Starting on September 7, Apple will begin removing old, outdated apps that have not received compatibility updates, do not comply with current review guidelines, or that no longer function as intended. This will see the elimination of many older apps that have been long abandoned.
Quality is extremely important to us. We know that many of you work hard to build innovative apps and update your apps on the App Store with new content and features. However, there are also apps on the App Store that no longer function as intended or follow current review guidelines, and others which have not been supported with compatibility updates for a long time. We are implementing an ongoing process of evaluating apps for these issues, notifying their developers, and removing problematic and abandoned apps from the App Store.Apps across all categories will be subject to Apple's new review process this September. Developers with problematic apps will be notified and will have 30 days to make changes to their app to prevent it from being removed from the App Store. Apps that crash on launch will, however, be removed from the App Store immediately.
Apple also plans to limit the number of characters that can be used in an app name, preventing some developers from using excessively long app names to influence search results. Beginning on September 7, app names submitted in iTunes Connect for both new apps and app updates will be limited to a maximum of 50 characters.
Search is one of the most frequently used methods for customers to discover and download apps from the App Store. In hopes of influencing search results, some developers have used extremely long app names which include descriptions and terms not directly related to their app. These long names are not fully displayed on the App Store and provide no user value. App names you submit in iTunes Connect for new apps and updates will now be limited to no longer than 50 characters.Over the course of the last few months, Apple has been dedicating resources to improving the App Store. In June, Apple announced plans to open up app subscriptions to all product categories, offer more favorable subscription revenue splits, improve sharing tools, and introduce ads to App Store search results to give developers new ways to promote their apps.
Update: Apple has also released updated App Store guidelines that cover new features in iOS 10 like SiriKit, sticker packs, Messages App Store, the new subscription policies, and more.