ReV, it was not animated for the following reasons:
-GIF's can only support so many colors, it will look shitty
-PNG's are much better since they load faster and look better (Portable.Network.Graphics
-You would have to go into the CSS code and change all the image references e.g "background:url(images/topNav.png);" to "background:url(images/topNav.gif);"
-Waste of time, animating 2 bars would take a while, replacing CSS, etc. It seems like a bit of a waste..
Although, good idea it would look nice.