I've read through what little documentation there is on Google's Swiffy page, and I don't see any way to pass FlashVars data to the HTML5 swiffyobject.
On an old version of a site there is this embed code (which uses SWFobject) to pass a javascript variable to Flash:
var mainmovie = new SWFObject("mainpage.swf", "themovie", "640", "480", "8", "#000099");
mainmovie.addParam("align", "middle");
mainmovie.addParam("wmode", "opaque");
mainmovie.addVariable("PageLayout", layoutCode);
mainmovie.write("target_div");
In other words, the variable PageLayout is passed to the Flash movie from .js
Is there some way to similarly pass javascript variables to swiffyobjects, either through something similar to SWFobject's addVariable, or through the standard FlashVars interface?