While Adobe will continue to support Flash Player 11.2 for Linux with security updates for several years, the company is moving to a framework it called Pepper which allows browser makers to directly integrated Flash into a web browser.
Right now Google is working with Pepper which means that future versions of Chrome for Linux will have Adobe Flash support baked in (much as Chrome web browsers for Windows and OS X already do). But Mozilla has no plans to integrate Pepper into Firefox.
Of course, the official Flash plugin isn’t the only game in town. Gnash, for instance, is an open source utility that can play Flash video.
But Flash also isn’t as prevalent as it used to be. Once upon a time, Flash was virtually the only game in town when it came to web video, but many of the top video sites have added support for HTML5 over the last few years as that platform has evolved… and as Apple has refused to add Flash support to the iPhone, iPod touch, or iPad.