If you have not already seen this article, you might be interested in it:
http://ianfeather.co.uk/ten-reasons-we-switched-from-an-icon-font-to-svg/
For backwards browser support and caching there is also the option to convert the svg file (just xml after all) into base64 and add it to the url in a CSS file. This is supported in IE 8 and allows IE to scale the svg image in all versions as well. It has the drawback of making the CSS file larger, but can be a single file load and be cached.
I don't know if the base64 version works with the concept of SVG classes that allows you to change the color of icons using CSS.
It is a definitely a good article and well argued.
For feature icons there is lotsa fun you can do with svgs, including animating paths with css.
Quick fun illustrating different branding colours applied to svg :
http://stuartlamour.com/mrooms/fun/allthesvg.html
(yeh - you will probably need to use a v.modern browser
But for generic icons, i think i still prefer to use an icon font.
The date one doesn't look as nice as the others. I'm suspecting a font issue due to me being on Ubuntu? (Though I don't see any flashing either so it may just be my version of Firefox is too old).
It seems like no-one talks about VML any more, has it just gone out of fashion or is it not up to the task of being a polyfill for SVG in IE8?
It seems like no-one talks about VML any more, has it just gone out of fashion or is it not up to the task of being a polyfill for SVG in IE8?