Assuming this article's suppositions are correct (that Google must become more social to continue growing), Google is showing a lot of cojones. Most businesses won't cannibalize their core cash-cow, even when they know the future is limited (see Kodak with digital cameras and every hard disk manufacturer :). There is no question it is a gamble; but if the other option is an eventual sunset (and I wouldn't be surprised if Larry thought of it that way), it is better to make the bet while you are on top than when you are scratching for survival.