What it could have been: Twitter, only more so–in Gmail.
Still extant? Yup. In fact, it’s part of Google+. But people seem pretty oblivious to it. (Or at least I am–it’s in my Gmail, and I never bother to check it.)
Want went wrong? Buzz got off to a truly hideous start, with a privacy dust-up that eventually resulted in an FTC fine. But even if had managed to avoid controversy, I’m not sure if the world would have embraced it. It’s based on two theories that seem to be faulty: (A) it’s possible to beat Twitter by providing more features, and (B) people want to engage in social sharing with their e-mail contacts.
Random trivia: The name “Buzz” seems to be jinxed. In April of this year, Yahoo killed Yahoo Buzz, a service that had nothing in common with Google Buzz–because it was a carbon copy of Digg.
Whew. Most of the history of Google+ is yet to be written. It might never put a serious dent in Facebook. But at least the chances seem pretty high that it won’t earn a spot in this Hall of Lame.