Just like Google, Bing has finally added a filter to their Bing Image search to filter images by animated GIFs only.
As many of you know, I love animated GIFs, so having two major search engines support an animated GIF filter, makes me happy.
Here is an example of filtering animated GIFs on Bing for [matt cutts] images.
If you hover your mouse over the image, it starts the animation. No need to click on it or go to the publisher's site.
Forum discussion at Google+.