On Tuesday, Google launched its would-be Facebook killer, Buzz, which uses your Gmail inbox to automatically establish a social network, and provides ways to share updates, pictures, etc, in a public or semi-public way.

Buzz has generated more buzz than anything since the iPad, but that’s only because the tech media world is already old in web years. All of us over 23 grew up using email as our primary virtual communication tool, and once your roots are down on the web, it’s pretty hard to move.

Those of us who have passed the quarter-century mark are thrilled with the idea of Buzz—no service knows our social graph better than Gmail, and if Google can use that implicit data to bust out Facebook-like sharing without any work on our part… dude, that’s so MacGyver.

But ever since 2006, teens have been abandoning email. Despite the astronomical growth of all things Web, comScore found that teen email use actually dropped 8% that year, and it’s remained anemic. Less than one-fifth of people aged 13-17 use e-mail as their primary communication method with friends, compared with nearly 40% of adults aged 25-54. Instant Messaging and social networks are the preferred means of virtual communication among teens. Email is only for talking to old people.

That means that Buzz does not solve Google’s “social problem.” Facebook and MySpace grew email-like functionality long before Gmail grew a social network. Buzz doesn’t provide any incentive for kids to start using Gmail. Their social graph resides elsewhere. At best, Buzz will give us 20- and 30-somethings a cool way to see what our old buds are up to, and it will stay relevant for a decade, but supplant Facebook it won’t.

Google’s roll in the social web is the same as in the web generally: filter and curate. Show users what’s most relevant to them based on a smart algorithm. Google is not and will never be the primary sharing tool—That’s Facebook, MySpace, Twitter. Both Buzz and Google’s Social Search Results show users the most relevant news from their social graph--and that's useful. Buzz, for instance, will import items from services like Twitter, but only show users the most important ones, weeding out lame tweets like “:p”.  That kind of filtering is powerful. But if teens can't post from Buzz to Facebook, which they can't, why in the world would they go to the trouble of switching back to email? No, Generation Y, Buzz is just for us.

Of course, even the social curation services are hampered by Google’s inability to mine Facebook, but that may change as Facebook pushes users to make more of their data public. Public is Google’s domain.