Aha! Getting google to return svg's instead of img's solved

So thanks to Mike William's post to the Google Maps API Google Group, I can get GPolygon to return svg's instead of img's in Firefox in Linux. Yay!

Basically, you have to set these two parameters, _mSvgEnabled and _mSvgForced to true in order to force Google to return SVG's. Here's the code snippet that made everything better:

function load() {
if (GBrowserIsCompatible()) {
// Initialize
if(document.implementation.hasFeature(
"http://www.w3.org/TR/SVG11/feature#SVG","1.1")){
_mSvgEnabled = true;
_mSvgForced = true;
}