Already posted, discussion <a href="http://news.ycombinator.com/item?id=4379867" rel="nofollow">http://news.ycombinator.com/item?id=4379867</a> and <a href="http://news.ycombinator.com/item?id=4375713" rel="nofollow">http://news.ycombinator.com/item?id=4375713</a> , and Google's blog post about it <a href="http://news.ycombinator.com/item?id=4375713" rel="nofollow">http://news.ycombinator.com/item?id=4375713</a>