Last we heard this was 'being tested by select advertisers'
What is the big issue here? Animated ads are quite standard at this point...if they are not confident people can make them dense enough, why not just have a size limit? What would be the editorial issue, too much 'noise'?
Obviously they stand to make more money if the CTR is higher - and for me the issue is really that ALL my banners are animated (and animated well, appropriately) and I do not have static versions to use with my content campaigns.