It was already reported that Flash wouldn’t be supported on Android 4.1 Jelly Bean and by that they meant you wouldn’t have the option to download it. However installing the APK on a supported device has shown to have little issues, although that can’t be said for everyone and Adobe aren’t going to fix any of that.
Adobe have completely pulled the trigger today and support for Flash on devices beyond 4.0.x and Adobe are urging those with newer devices not to install Flash for their devices as it may be unstable and cause undesirable results. The news that Flash will no longer be supported on mobile devices is something of a controversial moment, most people will miss flash but then again the movement towards HTML5 is something that has been gearing up for a long time and this move by Adobe will certainly push that along.
There are still a lot of very popular sites that still use flash and it is course a function that Android is known for, but hopefully HTML5 will become the standard sooner now that mobile flash is to be no more.