SVG does work with Safari: see
http://www.adobe.com/svg/viewer/install/svgtest.html (if you have the plug-in installed!). You don't have to do this, but using the contextual menu, select View SVG and you'll should get the SVG graphic in a separate window, where you can zoom in and out using the contextual menu.
I don't know what the problem with the Google implementation is, but considering the generally spotty results I get with SVG (mainly using iCab), I'd guess that it's a combination of things. I did see something recently about some work that was being done with Safari and SVG but can't remember more than that.
eMac Combo 1GHz/1GB/60GB Mac OS X (10.4.4) CanoScan D646U, Canon iP1600, CrossFire 120GB, DSL