Tagging is the next social networking
It's hot, it definitely changes user behavior, and it's like to result in huge winners and big losers.
For example, I'm amazed by how Digg managed to escape my notice until the recent announcement of its first round of VC. Now they're in BusinessWeek! I definitely plan on investigating further.
I also read about the unveiling of TagWorld in an article by one of my favorite journalists, Susan Kuchinskas (thanks again for the great article on my company!).
It seems like only yesterday that I was hearing about some newfangled service named Del.icio.us...
Of course, content isn't the only thing amenable to tagging. The whole space of online reputation management is simply another way of tagging people.
I think that tagging will be big because of the way it taps into free brainpower and collective wisdom, but no one really knows what its most important uses will be...yet.