Now those mailing lists weren't perfect, but they had some redeeming features-they were strictly opt-in, there was a clear reason for their formation (better than, say, being defaulted the 'India' network on Fb), they were reasonably simple to figure out if you knew how to use e-mail and the rules for posting and moderation within the network could be tweaked by the users themselves. Set against that was the pain of having loads of unread mails cluttering your inbox, including flame-wars, personal mails because people replied to the group instead of the sender and even the odd out-of-office auto-reply. Even today, most of the mails in my Gmail account in the last 6 months seem to be from members of a particular mailing list that I'm part of.
So now that Google's come out with Buzz and the initial enthusiasm has worn off, I find myself wondering why they didn't try integrating Buzz with Google Groups. Instead of opting users into one universal social network they could have provided a platform for multiple overlapping networks. People could choose which networks they wanted to join, what permission levels they wanted to set for the group, and they'd only need to share something once to the group. Instead of receiving 10 emails from members of a group with the same attachment being forwarded around with new comments, you could have just one instance of the item, with comments tacked on. Want to keep your work contacts different from your other friends? Set up different networks. With opt-in, there'd be less chances of twitter-style bots. And instead of those irritating messages on fb about '1 new survey for you to answer' etc, Google could simply show some discreet adwords on the side tailored for the network, similar to the ads shown within Gmail (maybe network members could even choose to some extent what types of ads they want to see=> more targeted ads =>happier marketers and customers).
It wouldn't necessarily be as flashy as facebook, but it could lead to more communicative networks, with more useful information.
Not to mention, it would reduce the chances of my being woken up at 1.00 AM because a new mail hit my phone, informing the mailing list that _______ is not in office right now and will be out on vacation with limited access to his e-mail, but we can contact his colleague _______ for any urgent matter.