As of August 15, Adobe Flash Player has been removed from the Google Play store. Those who already have Flash installed on their mobile devices will continue to receive security updates. Those devices which have not completed Adobe's certification testing requirements (according to Adobe this includes most devices which do not come with Flash pre-installed from the manufacturer) will not be able to acquire it in the future. Support for Flash has been dropped by all versions of Android beyond 4.0.x (ICS). Although this change does not immediately affect a large portion of users (some statistics show as few as 1.8% of users are currently on version 4.1), this presents a significant shift in the future of web development for the mobile platform.
The move coincides with the rise of HTML5 as a new cross-platform standard for multimedia and interactive web development. Flash Player has long been one of the more divisive features between competing Android and iOS platforms, for a while marketed as a distinct feature for non-iOS environments. However, security and stability issues, in part due to the aforementioned certification testing issues, have accelerated its decline. RIM plans to continue Adobe Flash Player support for its Blackberry OS tablet devices and Microsoft will include a truncated version of Flash in their Internet Explorer 10 "Metro" app, but that still makes for a relatively small presence in the mobile OS market.
While the discontinuation of Flash Player for Android is a significant milestone, it is important to note that Adobe is not abandoning mobile completely. Adobe AIR, a Flash-based runtime environment, will continue support and development on all platforms, including Android (v2.2+) and iOS. But distinct from Flash, AIR has a more limited presence, primarily used for app development instead of ubiquitous web media. In Adobe's own words from a whitepaper release, "This shift in focus for Flash does not mean that existing content will no longer run, or that Flash cannot be used for content other than gaming and premium video. However, it does mean that when prioritizing future development and bug fixes, gaming and premium video use cases will take priority." (source)
Overall, the end of Flash may hasten the rate at which developers choose to jump ship from using Adobe technology but will likely have negligible impact on OS market share. The primary significance will manifest in increased cross-platform functionality of web media. This is a good thing for the end user in the long term. But for now, plenty of legacy Flash content has just been effectively rendered obsolete.