Here's an article predicting some ways in which Facebook will further being to mimic Twitter: http://bokardo.com/archives/relationship-symmetry-in-social-networks-why-facebook-will-go-fully-asymmetric/
What this article is talking about is that in Facebook when you form a relationship with someone you follow each other. But in Twitter you can follow someone and they may or may not follow you. This analyst predicts Facebook will soon allow you to see someones news feed but not necessarily send them yours and vice versa.
This recharacterizes how we think about socialization on the net. Instead of reciprocal exchange we are transforming into personality feeds that people can subscribe to. One can imagine people in Facebook, as they are in Twitter, getting quite competitive as to whose life updates are the most interesting to the most people.