Q:

Does jQuery return true for :animated when the animation is a CSS transition?

Scenario: 

Trigger a CSS transition by changing an element's class via jQuery.
While the CSS transition is occurring, run if( $(elem).is(':animated') ) {…}

Will that if return as true?

A:

You could have try it yourself, but I was curious and tested it.
http://jsfiddle.net/udedV/
The answer is no.
Using :animated check if the element is currently in a queue.
CSS transition do not use queue, 
if( $(elem).is(':animated') )

It will alway be false if it is being animated by CSS.

