You cannot simply do something like
$("img").animate({
"WebkitTransform":"rotate(90deg)",
"MozTransform":"rotate(90deg)",
"Transform":"rotate(90deg)"
},1000);
At the moment, jQuery is not able to animate CSS3 Transform Values like rotate, translate, scale.
Use jQuery.animateTransform.js to animate CSS3 Transform-Values (translate, translate3d, rotate, skew, scale). The Plugin is an extension for jQuery's animate-function, hooking into $.fx.step to animate the CSS3 Transform-values. That means there's no need for using an own function with an own syntax. Just animate them the way you learned it.
$("img").animate({
"Something":somevalue,
"transform": {
rotate:90,
scale:1.5,
et cetera
}
},1000);
Visit my demo page for a detailed documentation and an interactive testing-tool.