Google's track record in terms of social media is not pretty. Consider the facts: Orkut never caught on in the U.S., Lively was killed after about six months, and so far, Buzz hasn't done much besides make people freak out. Still, Google's reportedly forging ahead by looking to hire a "Head of Social."
Liz Gannes obtained a recruiting letter describing this position, and Google was at least realistic in terms of expectations. Part of the letter acknowledged, "This is a new and very strategic position, as Google knows it is late on this front and is appropriately humble about it."
That's a smart admission on the company's part, since few intelligent people would want to feel they were facing an impossible task.
Then here's an interesting indicator of where Google might be heading: the letter continued, "In Google's view, conceptually, there are two ways to tackle social, each impacting who may be successful in this senior post: 1) building an innovative offering specifically in this area; or 2) developing the capability and integrating social into Google's existing portfolio."
So keep an eye out for personnel and product announcements in this field. And for that matter, try to get your application in to Google if you feel qualified. Gannes wrote that the company "is currently in the process of casting its net as widely as possible," and given all the embarrassment Google's suffered, it's no doubt willing to spend a fair amount of money to win over the right person.