Re: exposing CANVAS or something like it to Web Workers

That sounds like a reasonable approach to me. One thing missing is that
Workers would need something like requestAnimationFrame.

Any proposal that requires passing messages to the main thread to get
something on the screen fails to satisfy the huge need for games to be able
to get steady frame rates in the face of main-thread latency.

Rob
-- 
“You have heard that it was said, ‘Love your neighbor and hate your enemy.’
But I tell you, love your enemies and pray for those who persecute you,
that you may be children of your Father in heaven. ... If you love those
who love you, what reward will you get? Are not even the tax collectors
doing that? And if you greet only your own people, what are you doing more
than others?" [Matthew 5:43-47]