If you have the icons as svg you could also try raphaeljs [1][2]. It'll render the svg path as svg on most modern browsers and as vml on older IE browsers (ie6+). The added benefit is that raphael also does animations which enables you to animate your icons on browsers that don't support css3 animation.
[1] http://raphaeljs.com/icons/ [2] http://raphaeljs.com