My 2 cents on why Flash is irrelevant. Content is king. We all agree on this yes? People want that content through RSS, on a browser, on their phone, through email through etc etc... It must be open, sharable, free to see in any way the user wants.

Flash is merely one of these content delivery tools (often delivering it in a frustrating non-standard way). Repeat: a content delivery tool. Flash in itself is not content, aside from some visual senses when used as art or music or performance.

Now of course, the manner the content is delivered is important to some. Important to branding & marketing. That's an entirely nother topic. But to generalize, the manner of content delivery is becoming less and less relevant. A person wants to see a video or read an article. They want to read and write comments. They want to see related material. These are the absolute essentials, and Flash is absolutely unnecessary for this.

I do see one last branch that will save Flash until there is alternative. Streaming video. Live sports and events will be getting much much bigger in the near future. When there is an easier alternative, then Flash will be gone.