Shameless plug -- I'm making a HTML5 animation tool called Radi that outputs to canvas for realtime rendering. It also supports the <video> tag, so you can seamlessly mix vector graphics and pre-rendered video.

It's available as a free beta (currently Mac-only): http://radiapp.com

Looks very interesting, it would be great if you could put a video of the app in action on that page. I don't have a Mac so I can't try it out myself.

As far as I know, webkit supports hardware acceleration for CSS transforms - so maybe that's the reason.

also, svg still isn't supported on some browsers, including every android phone (android < 3.0)

A bigger questions is, how much are they going to charge for this.

I haven't looked at the browser support for Edge animations, but I'm guessing they're supporting earlier IEs, which limits what they can do.

It would be cool if they had a switch to render for only modern browsers.