The thing that worries me about this is the fact that I was already uncomfortable with the idea that Facebook might be making my private information public. For them to be integrating Twitter-like features doesn't exactly make me feel better. Twitters main draw seems to be in communicating with huge numbers of strangers while Facebook lets me talk to lots of friends at once.
Nothing is changing with privacy. Your updates are still only available to your friends (or whatever you set). The one-way follow is being added for real people to follow companies/public figures.
