Require developer accounts with authorization tokens to consume more than a set amount of CPU before the framework terminated your animation? Call it "Flash Pro" or something.
Then at least you've got an account on Joe frameloop ad.
So I would need a developer token to put up a flash animation on my website? I'm sure that would have killed adoption, and my hunch says that the ad agencies that were churning out the 100% CPU ads who dropped $799 on Flash could pay for the developer account anyways.
Then at least you've got an account on Joe frameloop ad.