Why would anyone even want a Gif replacement? Today they're mostly used for showing short clips of online videos -- when often (almost always) the full video version is a fraction of the size, has sound, shows more of the story, and has audio.<p>What personally amazes me is that people still use Gifs at all. Back in the day you'd see them as decorations on websites, but that role has been replaced by flash or using javascript for animations. Their only other advantage was transparency, but anyone who doesn't care for IE6 will just use a PNG instead since it offers superior alpha transparency.<p>Seriously, I don't see any reason to use Gifs these days and so see no reason why a replacement would even be desired.
Google claim to be adding this to WebP, despite the fact that it's derived from WebM, which is already a video format and therefor (you'd imagine) a superset of the features.