Slashdot videos: Now with more Slashdot!
The more interesting property relates to subscription. Like RSS, you start receiving updates from contacts you've explicitly selected. Spam-proof, and highly conducive to emergent conversations. (If you're a Facebook user, this is kind of like the News Feed.)
Here's another way to look at it: logging into your microblog is like joining an enormous IRC channel spanning the entire world, only almost everyone is set to