Interesting thought by Josh Constine. Perhaps the way for Google+ to find its audience is not by focusing on some small thing that Facebook or Twitter does and doing it better, but by going above them and focusing more broadly on making you connect socially with everyone.
The Circle problem remains though. For the massive network to work, you need Circles. And making them is fine, but no one is going to manage them. It will get messy — especially if people start following hundreds of thousands of other users.