Its nice to see that there are ways to do this on OSX. However, I hope Apple does not adopt this 'feature.' Over the years, my attitude towards desktop backgrounds has evolved. In the old Classic days, small patterns were the most efficient, so my background was usually a solid color. After OSX, I began to use all manor of images. Over the past year, I have found myself gravitating back towards plain colors, because of their simplicity. I find that this help the window content to stand out more. An animated background seem like it would visually compete with the window content too much.