TLDR/W: Hardware accelerated IE9 HTML5 canvas beats non-hardware accelerated Chrome 6 development HTML5 canvas.
It beat hardware accelerated chrome as well.
Firefox 3.7 actually came out on type by a bit in the end at a 1000 fish.
Worrying about canvas graphic acceleration without having a standard canvas implementation may be jumping the gun a little, although traditionally that is how HTML has been advanced. Its a case of premature optimization, but then there is potential for payoff in being first to market with a winning strategy...