4.1 doesn't (officially) support Flash.
However, they've been saying the latest plugin (4.0.3+) works on 4.1 flawlessly.

So I guess Flash isn't dead. And the next iteration of (major, not incremental) Android would certainly break compatability. Though I guess there will be some sort of open-source effort which might bring it back.

However, that will be a short lived feature, afterwards its certainly gone for good.
The only way you'd be able to have Flash after that, is if a reputable company (Opera/Firefox) actually incorporates it into their App: web browser. It would be clunky for most things, but online videos may still work.